Question

I told Sally how to get there, but perhaps I ________ for her.

A．had to write it out

B．must have written it out

C．should have written it out

D．need to have written it out

Answer 1

C

试题分析：考查情态动词+完成式的用法：句意：我告诉Sally怎么到这儿，但是可能我应该把它写下来。本应该做而没做should have done，must have done过去一定做了，need 后面直接接have done，没有to，选C。
点评：情态动词无论是表达“推测和可能性”，还是表达“虚拟”这一概念，只要是对过去已经发生的事情进行描述，一律用“情态动词+have done”这一结构；对现在或将来的事情进行描述，用“情态动词+动词或系动词原形”。