题目：
----- It was a red light, William. You ________ the car.
------- Sorry, I didn’t see it.
A．must stop
B．should stop
C．must have stopped
D．should have stopped
答案：
答案：D
考察情态动词，根据it was 和I didn't see it可知，该句是对过去的虚拟，所以排除AB。C意为一定做了某事 D意为本应当做某事
句意为，---当时是红灯，威廉，你本应当把车停住的。----对不起，我没看见。
