问题补充：
—What are you doing, John? Why stop?
—To be on the safe side, we’d fill up the car now for we run out of gas on the way．
A. must
B. will
C. might
D. should
答案：
A. must
B. will
(答案→)C. might
D. should
解析：情态动词考查题。A．must 肯定推测“一定”B．will将会C．might 表推测语气轻“也许” D．should 表示按常理推测“应该”句意：约翰，你在干什么？为什么停车？为安全起见我们最好加满油因为在路上也许会用光的。根据语境选C
