Question

【题目】We be careful when we're walking across the road. There're too many cars now.

A. can B. may C. must D. could

Answer 1

【答案】C

【解析】句意：当我们正穿过马路时，我们一定要小心。现在有太多的汽车。can可以，表示允许；may可以，表示允许；must一定，表示要求；could可以，表示委婉的请求。根据There're too many cars now.可知马路上有很多汽车，因此过马路时一定要小心，这是一种要求，故用情态动词must，故选C。