New 清華大學圖書館 · 2019. 2. 22. · (C) C10H13Cl singlet, 1.57, 6H; singlet, 3.02; singlet, 7.27, 5H (D) C3H5C13 singlet, 2.20, 3H; singlet, 4.02, 21-1 How many pairs of