题目

下列有机物命名正确的是: A．                    1，3，4-三甲苯    B．                 2-甲基-2-氯丙烷 C                    2-甲基-1-丙醇      D．                  2-甲基-3-丁炔 答案：BSingle-parent usually____ some of the functions that absent adult in the house would have served under the financial crisis. A. takes over          B. takes after           C. takes out           D. takes in