My English teacher insisted that the exercises very difficult and that we them carefully.A

网友回答

A. were; must finish
B. be; finish
(答案→)C. were; finish
D. be; finished
解析：根据句子结构可知，and前的部分表述的是观点，故用一般过去时；第二空表达的是建议，故用should+动词原形的形式，should被省略。句意：我的英语老师坚持认为这些练习很难，我们应该认真完成它们。