1. I was reading the paper____she was writing. A.when B.as C.while D.after 老师!以上题我觉得A B C都可以
【答】答案是 C.while
2. When you read the book you had better make a mark____you have any questions.
A.at which B.at where C.the place where D.where
老师!以上题我觉得C D都可以
【答】答案是D.where,也可以填 in the place where,所以不能选择 C.the place where。