问题
选择题
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
答案
答案：D
题目分析：考查情态动词。must have done 肯定做了某事，表示对过去的肯定推测。句意：蛋糕非常甜，你肯定在里面放了很多糖。所以选D。could have done 本可以做而没做