题目

—I guess it must be pretty hot in Hong Kong in summer, isn’t it?        —Yes. That’s why we      to Beijing. But we didn’t know it        so cold here in winter.        A．are moving; was             B．moved; would be        C．have moved; is        D．were moving; has been 答案：B有A、B两种元素，其相对原子质量分别56和16，化合价分别为+3价和-2价，则A和B组成的化合物的相对分子质量是A. 200 B. 160 C. 88 D. 72