——How do you find the cake?
——This cake is very sweet. You a lot of sugar in it.
A. should put
B. could have put
C. might put
D. must have put
网友回答
A. should put
B. could have put
C. might put
(答案→)D. must have put
解析：考查情态动词用法。情态动词+动词原形表示在现在情况的推测；情态动词+have done表示对过去情况的推测。本题蛋糕很甜，说明放了很多的糖是在过去发生的事情，排除AC。Must have done一定做了某事。Could have done可能做了某事，句意你认为蛋糕怎么样？—非常甜。你一定放了很多的糖。故Ｄ正确。