—Whatareyoudoing,John?Whystop?  —Tobeonthesafeside,we'...

问题详情：

 — What are you doing, John? Why stop?

   — To be on the safe side, we'd fill up the tank now for we _______ run out of gas on the way

A. must            B. will           C. might          D. should

【回答】

C

知识点：情态动词

题型：选择题