---Mary is a careful girl---Yes. She always goes over her exercises to there are no mista

问题补充：

---Mary is a careful girl．

---Yes. She always goes over her exercises to there are no mistakes．

A. look for

B. make sure

C. find out

D. think about

答案：

A. look for

(答案→)B. make sure

C. find out

D. think about

解析：look for寻找；make sure确信，证实；find out找出，查明；think about考虑。句意：玛丽是个细心地女孩。——是的，她总是检查她的练习题来确定没有错误。结合语境可知选B。