题目

The comments the expert made ______ stock-market bothered him greatly, ______ him not fall asleep all night.    A. concerning, making                                       B. be concerned, which made C. concerned, making                                    D. to be concerning, made 答案：A。 解析: concerning关于，这里为介词；making和the meeting形成主动关系。化学符号“2H2”表示（ ）A.两个氢分子B.两个氢原子C.两个氢元素D.氢气