问题
选择题
Joan stood outside a shopping mall for a long time, as if ________ somebody.
A．to wait for
B．waiting for
C．waited for
D．having waited for
答案
答案：B
题目分析：考查非谓语动词。Joan和wait是主谓关系，用现在分词表主动和伴随状况，排除C；动词不定式表示目的，不符合语境，排除A；having done是现在分词的完成时，表示动作有先后，这里的stood和wait是同时发生的，排除D。waiting for相当于he was waiting for。故选B。