问题补充:
---The book is borrowed from the library. You your children touch it with their dirty hands.
---Sorry.
A. should have let
B. needn’t have let
C. mustn’t have let
D. ought not to have let
答案:
A. should have let
B. needn’t have let
C. mustn’t have let
(答案→)D. ought not to have let
解析:考查情态动词。ought not to have done本不应当做某事。句意:——书借自图书馆,你本不应当让孩子用脏手碰它。——对不起。