She is a diligent student, and all her spare time she has staying in the library．
A. is spent
B. spent
C. to spend
D. to be spent
网友回答
(答案→)A. is spent
B. spent
C. to spend
D. to be spent
解析：考察定语从句。本句中定语从句省略that，句中主语her spare time为抽象名词，不可数，故谓语动词用单数。选A，她有的所有的空闲时间都花在泡图书馆了。