When I was at school I up very late reading storybooks.A. used to stayB. was used to st

问题补充：

When I was at school, I up very late, reading storybooks.

A. used to stay

B. was used to stay

C. used to staying

D. am used to staying

答案：

(答案→)A. used to stay

B. was used to stay

C. used to staying

D. am used to staying

解析：考查短语搭配。used to do sth.过去常常做某事。句意：当我上学的时候，我常常看小说而睡得很迟。