Question

If _______ to look after luggage for someone else, inform the police at once

1. A.
   asked
2. B.
   to ask
3. C.
   asking
4. D.
   having asked

Answer 1

A
试题分析:考查非谓语动词。由结构分析可知前面部分是分词做状语，ask和句子主语之间是被动关系，所以用过去分词，此处也可以看做是状语从句if you are asked to look after luggage的省略。句意：如果有人让你照看行李，要立刻通知警察。
考点：考查非谓语动词。