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Objectives• Distinguish between renewable and nonrenewable
resources.
What are resources?
• Identify renewable and nonrenewable resources.
– natural resource
– renewable resource
– sustainable yield
– nonrenewable resource
Vocabulary
• In addition to food and water, most animals also need shelter.
What are resources?• You and every other living thing on Earth must
have certain resources to grow, develop, maintain life processes, and reproduce.
What are resources?
Natural Resources• Natural resources are the resources that Earth
provides, including air, water, and land; all living things; and nutrients, rocks, and minerals in the soil and deep in Earth’s crust.
What are resources?
• Neither matter nor energy can be created or destroyed, but both can be changed from one form to another.
• Natural resources are changed through cycling, as in the carbon, nitrogen, and water cycles.
Renewable Resources• Renewable resources are natural resources
that can be used indefinitely without causing a reduction in the available supply.
What are resources?
• Resources that exist in an inexhaustible supply, such as solar energy, also are renewable resources.
• Renewable resources are replaced through natural processes at a rate that is equal to, or greater than, the rate at which they are being used.
Renewable Resources
Living Things
What are resources?
– Plants and animals reproduce, and therefore, as long as some mature individuals of a species survive, they can be replaced.
– Humans who use natural resources responsibly are practicing management techniques to replace resources as they are used.
– A sustainable yield results when renewable resources are replaced at the same rate at which they are consumed.
Renewable Resources
Sunlight
What are resources?
– The Sun provides an inexhaustible source of energy for all processes on Earth.
– Sunlight is considered to be a renewable resource because it will continue to be available for at least the next 5 billion years.
Nonrenewable Resources• A nonrenewable resource is a resource that
exists in a fixed amount in various places in Earth’s crust and can be replaced only by geological, physical, and chemical processes that take hundreds of millions of years.
What are resources?
• Nonrenewable resources are exhaustible because they are being extracted and used at a much faster rate than the rate at which they were formed.
Distribution of Resources• Natural resources are not distributed evenly
on Earth.
What are resources?
• The availability of natural resources helps determine the wealth and the power of countries around the world.
• The United States has a high standard of living and it consumes approximately 30 percent of Earth’s mineral and energy resources each year, even though it has only 6 percent of the world’s population.
Distribution of ResourcesThis graph shows the percentage of crude oil that is consumed by the United States and worldwide. Note that the United States consumes 27 percent of the total crude oil used each day.
What are resources?
Section Assessment
1. Match the following terms with their definitions.
___ natural resource
___ renewable resource
___ sustainable yield
___ nonrenewable resource
What are resources?
A. a resource that Earth provides
B. a resource that exists in a fixed amount that is not easily or quickly replaceable
C. a resource that is replaced at a rate equal to, or greater than, the rate at which it is being used
D. the result of replacement of a resource at the same rate in which it is consumed
A
C
D
B
Section Assessment
2. Under what condition is a living organism a renewable resource?
What are resources?
Plants and animals must be able to reproduce in order to be a renewable resource. As long as some mature individuals of a species survive, they can be replaced.
______ Diamonds are an example of a renewable resource since more will be formed over time.
______ The use of nonrenewable resources can be managed in such a way to create a sustainable yield.
______ The United States uses over half of the Earth’s mineral and energy resources each year.
______ Small countries can have abundant natural resources.
Section Assessment
3. Identify whether the following statements are true or false.
What are resources?
false
false
false
true
Objectives• Describe why land is considered to be a natural resource.
• Recognize the need to protect Earth’s land as a resource.
• Explain how humans adjust to the uneven distribution of land resources.
– desertification
– bedrock
– aggregate
– ore
– gangue
Vocabulary
Land Resources
Land Resources• Land is a valuable natural resource.
Land Resources
– Land provides places for humans and other organisms to live and interact.
– Land also provides spaces for the growth of crops, forests, grasslands, and for wilderness areas.
Protected Land• Of all the land in the United States, 42 percent is
certified as public land, which consists of forests, parks, and wildlife refuges.
Land Resources
• These land areas are federally administered to protect timber, grazing areas, minerals, energy resources, and recreational interests.
• National forests are managed for sustainable yield and include multiple-use areas where resources are used for many purposes, including recreation.
Protected Land• Wilderness areas are places that are maintained
in their natural states and protected from development.
Land Resources
• The national park system preserves scenic and unique natural landscapes, preserves and interprets the country’s historic and cultural heritage, and provides areas for various typesof recreation.
• National wildlife refuges provide protection of habitats and breeding areas for wildlife, and some provide protection for endangered species.
Soil• It can take up to 1000 years to form just a few
centimeters of topsoil, yet it can be lost in a matter of minutes as a result of erosion by wind or water.
Land Resources
• The loss of topsoil makes soil less fertile and less able to hold water, which results in poorer crops.
• Topsoil is currently eroding faster than it forms on about one-third of Earth’s croplands.
Soil• Desertification, which can occur in arid and semi-
arid areas of the world, is the process whereby productive land becomes desert.
Land Resources
• Desertification can be prevented by reducing overgrazing and by planting trees and shrubs to anchor soils and retain water.
Bedrock• Underneath the topsoil is a layer of soil consisting
of inorganic matter, including broken-down rock, sand, silt, clay, and gravel.
Land Resources
• Bedrock is a base of unweathered parent rock underlying the soil that may consist of limestone, granite, marble, or other rocks that can be mined in quarries.
Aggregates• An aggregate is a mixture of gravel, sand, and
crushed stone that naturally accumulates on or close to Earth’s surface.
Land Resources
• Aggregates are found in river valleys, in alluvial fans, and in glacial moraines, eskers, kames, and outwash plains.
• Aggregates used in construction are mixed with cement, lime, gypsum, or other materials to form concrete or mortar.
• The most commonly used natural aggregates are sand, crushed or broken rocks, and gravel.
Ores• An ore is a useful, natural resource that can be
mined at a profit.
Land Resources
• Ores can be classified by the manner in which they formed.
• Some ores are associated with igneous rocks, whereas others are formed by processes at Earth’s surface.
Ores
Settling of Crystals
Land Resources
– Ores associated with igneous rocks may contain iron, chromium, and platinum.
– Chromium and platinum ores can form when minerals crystallize and settle to the bottom of a cooling body of magma.
Ores
Hydrothermal Fluids
Land Resources
– Hydrothermal fluids are the most important sources of metallic ore deposits.
– Atoms of metals such as copper and gold do not fit into the crystals that form during the cooling process and become concentrated in the remaining magma.
– Eventually, a solution rich in metals and silica moves into the surrounding rocks to create ore deposits, known as hydrothermal veins, along faults and joints.
Ores
Chemical Precipitation
Land Resources
– Ores of manganese and iron most commonly originate from chemical precipitation in layers.
– Iron ores in sedimentary rocks are often found in bands made up of alternating layers of iron-bearing minerals and chert called banded iron formations.
Ores
Placer Deposits
Land Resources
– Heavy sediments, such as grains of gold and silver, may be deposited in bars of sand and gravel when stream velocity decreases.
– Placer deposits are sand and gravel bars that contain heavier sediments such as gold nuggets, gold dust, diamonds, platinum, and gemstones, as well as rounded pebbles of tin and titanium oxides.
Ores
Concentration by Weathering
Land Resources
– Some ores form when the minerals in rocks are concentrated by weathering.
– Aluminum forms in bauxite through weathering in tropical climates.
– Other metals that become more concentrated as rocks weather include nickel, copper, silver, lead, tin, mercury, uranium, and manganese.
Other Land Resources• Clay is used to make bricks, china, ceramics, tiles,
and pottery.
Land Resources
• Salt, or sodium chloride, occurs in deposits both on Earth’s surface and underground.
• Deposits of both salt and gypsum, which is used to make plaster, can form when seawater evaporates.
Using Land Resources• The extraction of some resources can have
negative impacts on the surrounding environment.
Land Resources
– Mines can destroy the original ground contours and leave behind waste rock that can release pollutants.
– Gangue, which is the material left after ore is extracted through grinding the parent rock, may release harmful chemicals into groundwater or surface water.
– Mercury is used to extract gold from alluvial deposits.
– Materials that form acids as they weather, such as pyrite, can be exposed through mining.
– Mining has been identified as the most dangerous occupation in the United States.
Section Assessment
1. Match the following terms with their definitions.
___ bedrock
___ aggregate
___ ore
___ gangue
Land Resources
A. a mixture of gravel, sand, and crushed stone that naturally accumulates close to Earth’s surface
B. material left over after ore is extracted
C. the base of unweathered parent rock beneath soil
D. a natural resource that can be mined at a profit
C
A
D
B
Section Assessment
Land Resources
2. What is desertification and how can it be prevented?
Desertification is the process whereby productive land becomes desert. It can be prevented by reducing overgrazing and by planting trees and shrubs to anchor soils and retain water.
Section Assessment
3. Identify whether the following statements are true or false.
Land Resources
______ Platinum is often found near the bases of sills and other igneous intrusions.
______ Major aluminum deposits are likely located in the Rocky Mountains.
______ Of all the land in the United States, 22 percent is certified as public land.
______ It can take up to 1000 years to form just a few centimeters of topsoil.
true
false
false
true
– pollutant
– air pollution
Objectives• Recognize that the atmosphere is an Earth resource.
• Describe the importance of clean air.
Vocabulary
Air Resources
Air Resources• Air contains substances that all organisms need
to survive, including nitrogen, carbon dioxide, hydrogen, helium, methane, ozone, neon, and argon.
Air Resources
• Water vapor can make up as much as five percent of air by volume.
• For animals, the most important component of air is oxygen.
Origin of Oxygen• Most organisms on Earth require oxygen or
carbon dioxide to maintain their life processes.
Air Resources
– Scientists hypothesize that 4.6 to 4.5 billion years ago, Earth’s atmosphere included primarily carbon dioxide, nitrogen, and water vapor.
– Early life-forms in the seas used carbon dioxide during photosynthesis and released oxygen and water vapor.
– Over time, oxygen in the atmosphere built up to levels that allowed the evolution of organisms that required oxygen for life processes.
Disrupting Earth’s Cycles• The geochemical cycles of Earth’s atmosphere
are in a delicate balance.
Air Resources
– Volcanic eruptions release various gases and dust particles into the atmosphere.
– Photosynthetic organisms in the oceans and on land take in and use carbon dioxide and release oxygen.
– Other organisms take in this oxygen and release carbon dioxide.
Disrupting Earth’s Cycles• Human activities that release carbon dioxide into
the atmosphere, such as burning fossil fuels, can disrupt the geochemical cycles.
Air Resources
• Global warming, which is the gradual rising of Earth’s average surface temperature, may be one result of the human alteration of the carbon cycle.
• Deforestation has changed precipitation patterns in the tropical rain forests of the Amazon River Basin.
Disrupting Earth’s CyclesIn the Amazon River Basin, scientists estimate that 1 hectare (ha, about 2.47 acres) of rain forest is cut down each hour. Nearly 20 million ha of rain forest is destroyed each year worldwide. This graph indicates the fate of the world’s tropical rain forests if the current rate of deforestation continues.
Air Resources
Disrupting Earth’s Cycles• Nitrogen oxides released by human activities are
converted to nitric acid, which returns to Earth in acid precipitation.
Air Resources
• Sulfur released into the atmosphere is converted to sulfuric acid, which also forms acid precipitation.
• Pollutants are substances that can adversely affect the survival, health, or activities of organisms.
• Air pollution results when pollutants in air occur in quantities that become harmful to human health and the health of the environment.
Sources of Air Pollution• Air pollution has both natural and human origins.
Air Resources
– Natural sources of air pollution include volcanic eruptions and forest fires.
– Human sources of air pollution include gases, smoke, and dust.
– The largest human source of air pollution is the burning of fossil fuels in power plants and motor vehicles.
– In some large cities, motor vehicles are responsible for 80 to 88 percent of the air pollution.
Sources of Air Pollution• When humans inhale harmful gases, the gases
can be absorbed by the bloodstream and interfere with various body systems.
Air Resources
• Pollution can also cause burning eyes, irritated throats, and breathing difficulties.
• As clean air in the troposphere moves across Earth’s surface, it collects both naturally occurring and human-made pollutants.
Sources of Air Pollution
Transport and Dilution
Air Resources
– Transport of pollutants downwind from their origin depends upon wind direction and speed, topographical features, and the altitude of the pollutants.
– If air movement in the troposphere is turbulent, some pollutants are diluted and spread out, which reduces their concentration.
Sources of Air Pollution
Transformation and Removal
Air Resources
– Some pollutants undergo chemical changes, called photochemical changes, that are triggered by reactions with ultraviolet (UV) radiation.
– Some air pollutants can undergo physical changes and become heavy enough to fall back to Earth’s surface.
– Air pollutants are removed from the atmosphere in precipitation, which includes snow, mist, and fog, as well as rain.
Indoor Air Pollution• About 90 percent of the furniture sold in the
United States also contains formaldehyde, which is just one of the many air pollutants that occurs indoors.
Air Resources
Indoor Air Pollution
Air Resources
Indoor Air Pollution
“Sick” Buildings
Air Resources
– Indoor air pollutants have been linked to headaches, coughing, sneezing, burning eyes, nausea, chronic fatigue, and flulike symptoms.
– A building is said to be “sick” when these symptoms are experienced by 20 percent of its occupants.
– Often, these symptoms disappear when the affected people go outside.
– New buildings are more likely to be “sick” than older buildings.
Indoor Air Pollution
Radon Gas
Air Resources
– Radon-222 is a colorless, odorless, and tasteless naturally occurring gas produced by the radioactive decay of uranium-238.
– Outdoors, radon gas seeps from the ground into the atmosphere, where it is diluted to harmless levels.
– Radon gas can enter through cracks in a foundation and build up to high levels indoors.
– Once indoors, radon gas decays into radioactive elements that can be inhaled, causing an increased risk of lung cancer.
Section Assessment
1. What is the single largest source of air pollution in the United States?
Air Resources
The largest source of air pollution in the United States is the exhaust from motor vehicles that burn fossil fuels in the form of gasoline.
Section Assessment
2. How are air pollutants removed from the atmosphere?
Air Resources
Air pollutants are removed from the atmosphere in precipitation, which includes snow, mist, and fog, as well as rain.
Section Assessment
Air Resources
3. Identify whether the following statements are true or false.
______ Natural processes release about three times as much nitrogen oxide and ammonia gas into the atmosphere as do human activities.
______ Newer buildings are more likely to be “sick.”
______ Radon-222 is generally harmless outdoors.
______ Nearly 5 million ha of rain forest is destroyed each year worldwide.
false
true
true
false
• desalination
Objectives• Explain the importance of clean freshwater.
• Analyze how water is distributed and used on Earth.
• Identify ways in which humans can reduce the need for increasing production of freshwater resources.
Vocabulary
Water Resources
Water Resources• The oceans contain 97 percent of the planet’s
water, which means that only 3 percent of Earth’s water is freshwater.
Water Resources
• Of this freshwater, about 2.997 percent is either locked up in ice caps and glaciers or stored as groundwater that is too deep to extract.
• Only 0.003 percent of Earth’s total volume of water is available to humans for domestic, agricultural, and industrial purposes.
The Importance of Water• About 71 percent of Earth’s surface is covered
by water.
Water Resources
• The oceans help regulate climate, provide habitats for marine organisms, dilute and degrade many pollutants, and help shape Earth’s surface.
• Freshwater is an important resource for agriculture, transportation, recreation, and numerous other human activities.
• Most animals are about 50 to 65 percent water by weight, and even trees may be composed of up to 60 percent water.
The Importance of Water
Liquid Water
Water Resources
– Water can exist as a liquid over a wide range of temperatures because of the hydrogen bonds between water molecules.
– The hydrogen bonds cause water’s surface to contract and allow water to adhere to and coat a solid.
– Water also has a high boiling point, 100°C, and a low freezing point, 0°C.
The Importance of Water
Heat Storage Capacity
Water Resources
– Liquid water can store a large amount of heat without a correspondingly high increase in temperature.
– This property protects organisms that live in water from abrupt temperature changes, and it is also responsible for water’s ability to regulate Earth’s climate.
– Water absorbs large quantities of heat as it changes into water vapor.
The Importance of Water
Water as a Solvent
Water Resources
– Liquid water can dissolve a wide variety of compounds.
– This ability enables water to carry nutrients into, and waste products out of, the tissues of living things.
– Water also dilutes water-soluble waste products of humans and thus serves as an all-purpose cleanser.
The Importance of Water
Solid Water Expands
Water Resources
– Water expands when it freezes.
– Because ice has a lower density than liquid water, it floats on top of water causing bodies of water to freeze from the top down.
– Ice forming in existing cracks can fracture rocks, thus becoming part of the weathering process.
Location of Freshwater Resources• Freshwater resources are not distributed evenly
across Earth’s landmasses.
Water Resources
– Although the United States has plenty of freshwater, much of it is concentrated in the eastern states or has been contaminated by agricultural or industrial processes.
– Worldwide, water distribution is a continuing problem, even though most continents have plenty of water.
– About 25 countries, primarily in Africa, experience chronic water shortages.
Location of Freshwater Resources
Countries experience severe water stress when there is less than 1000 m3 of freshwater per person. Extreme water stress occurs when there is less than 500 m3 of freshwater per person.
Water Resources
Use of Freshwater Resources• The current rate of withdrawal of freshwater from
both surface and groundwater sources worldwide is five times greater than it was just 50 years ago.
Water Resources
– About 70 percent of the water withdrawn each year is used to irrigate 18 percent of the world’s croplands.
– About 23 percent of freshwater is used for cooling purposes in power plants, for oil and gas production, and in industrial processing.
– About 7 percent goes to domestic and municipal uses.
Use of Freshwater Resources
Water Resources
Managing Freshwater Resources• Most countries manage their supplies of
freshwater by building dams, transporting surface water, or tapping groundwater.
Water Resources
• Some countries also have had success removing the salts from seawater to provide needed freshwater supplies.
Managing Freshwater Resources
Dams and Reservoirs
Water Resources
– Building dams is one of the primary ways that countries try to manage their freshwater resources. • Large dams are built across river valleys, usually to control flooding downstream.
• Reservoirs behind dams capture the rivers’ flow, as well as rain and melting snow.
• Dams and reservoirs currently control between 25 and 50 percent of the total runoff on every continent.
Managing Freshwater Resources
Transporting Surface Water
Water Resources
– Many countries use aqueducts, tunnels, and underground pipes to bring water from areas where it is plentiful to areas in need of freshwater supplies.
• The California Water Project transports water from northern California to southern California.
• There is a demand for even more water to be diverted to the south to which the residents of northern California object.
• Conflicts over the transport of surface water will probably increase as human populations create higher demands for water.
Managing Freshwater Resources
Tapping Groundwater
Water Resources
– In the United States, about 23 percent of all consumer freshwater consists of groundwater pumped from aquifers.
– Groundwater normally moves from points of high elevation and pressure to points of lower elevation and pressure at a rate of only about 1 m/year.
– Drawdown occurs when the withdrawal rate of an aquifer exceeds its natural recharge rate, and the water table is lowered.
– Groundwater depletion can affect stream flow and can result in the intrusion of salt water into shallow aquifers in coastal areas.
Managing Freshwater Resources
Desalination
Water Resources
– Desalination is the process of removing salt from ocean water to provide freshwater.
– Desalination occurs when salt water is distilled.• The water is first heated until it evaporates, then it
is condensed and collected.
• The evaporation process leaves the salts behind.
• Most countries that use desalination to produce freshwater use solar energy to evaporate sea water.
Managing Freshwater Resources
Reducing Freshwater Use
Water Resources
– The best way to meet the need for freshwater is to use available supplies more efficiently. • Farmers can prevent evaporation of irrigation water by using irrigation methods such as
trickle irrigation.
• Industries can use recycled water instead of clean freshwater for manufacturing processes.
• Many domestic uses can be reduced by installing low-flow toilets, using plants that are drought-resistant for landscaping, and fixing leaky pipes and faucets.
Section Assessment
1. Agriculture accounts for what percentage of freshwater use worldwide?
a. 30 percent c. 70 percent
b. 50 percent d. 80 percent
Water Resources
2. Where are most countries that experience water shortages located?
a. Europe c. Asia
b. South America d. Africa
Section Assessment
Water Resources
3. Identify whether the following statements are true or false.
______ About 3 percent of Earth’s water is freshwater that is available for human use.
______ The current rate of freshwater withdrawal is five times greater than it was 50 years ago.
______ Dams and reservoirs currently control between 50 and 75 percent of the total runoff on every continent.
______ Groundwater generally moves through the ground at a rate of 1 m/year.
false
true
false
true
Chapter Resources Menu
Chapter Resources Menu
Study Guide
Section 25.1
Section 25.2
Section 25.3
Section 25.4
Chapter Assessment
Image Bank
Section 25.1 Main Ideas• Natural resources are the resources that Earth provides,
including air, water, land, organisms, rocks, minerals, and nutrients.
• Renewable resources are replaced by natural processes at a rate that is equal to or greater than the rate at which they are being used.
• Nonrenewable resources exist in a fixed amount and can be replaced only by geological, physical, and chemical processes that take hundreds of millions of years.
Section 25.1 Study Guide
Section 25.2 Main Ideas• Land resources include topsoil, rocks, and minerals. Land
also provides space for agriculture, housing, roadways, and protected areas such as national forests, wildlife refuges, and national parks.
• Topsoil is a complex mixture of decaying organic matter, eroded rock, minerals, nutrients, oxygen, and water. In arid areas, loss of topsoil can lead to desertification.
• Bedrock is unweathered parent rock.
• Aggregates, including sand, gravel, and crushed stone, are found in glacial deposits.
• An ore is a natural resource that can be mined at a profit. Ores may be associated with igneous rocks or formed by processes at Earth’s surface.
Section 25.2 Study Guide
Section 25.3 Main Ideas• The atmosphere contains mostly nitrogen and oxygen,
as well as various other gases in smaller amounts. Early Earth had no oxygen; this was supplied by photosynthetic organisms.
• The geochemical cycles of Earth’s atmosphere are delicately balanced. Human activities disrupt this balance, and air pollution results.
• Clean air is necessary to most organisms. Both outdoor and indoor air pollution are harmful to living things.
Section 25.3 Study Guide
Section 25.4 Main Ideas• Freshwater is necessary to all life and to many Earth
processes. Water is recycled continually through the water cycle.
• Water has unique properties that allow life to exist on Earth.
• Water is not evenly distributed on Earth’s surface.
• Water-management methods distribute freshwater resources more evenly through the use of dams, aqueducts, and wells.
Section 25.4 Study Guide
1. Which of the following is a nonrenewable resource?
a. copper c. solar energy
b. trees d. water
Multiple Choice
Chapter Assessment
Copper is a nonrenewable resource because it exists in limited supply. Trees, solar energy, and water are renewable resources because they either reproduce or are available in a nearly inexhaustible supply.
2. What is the primary criteria in defining an ore?
a. it is widely available
b. it is commercially useful
c. it can be mined at a profit
d. it is igneous in origin
To be an ore, the resource must be able to be mined at a profit. This means that its value on the market is greater than the cost of extraction.
Multiple Choice
Chapter Assessment
Multiple Choice
3. Which of the following is an aggregate?
a. sand c. limestone
b. marble d. granite
Chapter Assessment
An aggregate is a mixture of gravel, sand, and crushed stone that naturally accumulates on or close to Earth’s surface. Marble, limestone, and granite are examples of bedrock, which is solid rock that can be mined in quarries.
Multiple Choice
4. In the United States, what percentage of carbon monoxide pollution is caused by motor vehicles?
a. 50 percent c. 80 percent
b. 60 percent d. 90 percent
Chapter Assessment
In addition to 90 percent of all carbon monoxide pollution, motor vehicles are also responsible for 80 to 88 percent of all air pollution in some major cities.
Multiple Choice
5. Most countries that use desalination to produce fresh water use ____ to evaporate sea water.
a. fossil fuels c. solar energy
b. wind energy d. conservation
Chapter Assessment
Solar energy, although a slow method, is the preferred energy source to evaporate sea water because it is inexpensive. Some desalination plants use fuel, but because this process is expensive, it is used primarily to provide drinking water.
Short Answer
6. Which property of water has the greatest impact on climate?
Chapter Assessment
The ability to store a large amount of heat without a correspondingly high increase in temperature is responsible for water’s ability to regulate Earth’s climate.
Short Answer
7. How does the energy consumption of the United States compare with the rest of the world?
Chapter Assessment
The United States, with only six percent of the world’s population, consumes 30 percent of Earth’s energy and mineral resources. The United States consumes more of these resources than any other country.
True or False8. Identify whether the following statements are true or
false.
______ Limonite is an example of an ore because it contains iron.
______ The gases released from a volcanic explosion are considered air pollution.
______ Rates of freshwater withdrawal are expected to triple within the next 20 years.
______ Placer deposits are a good place to look for gold nuggets.
______ Over 60 percent of the land in the United States is certified as public land.
Chapter Assessment
false
true
false
true
false
Image Bank
Chapter 25 Images
Image Bank
Chapter 25 Images
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