1 . I have some doubt _______ what he said at the party was true or not. （用适当的词填空）

2 . The people ________ faces lit up with a huge smile gave me the deepest impression. (用适当的词填空)

5 . Swimming is good for teenagers, ______ some experts say will help them to stimulate their potential and promote their brain development. (用适当的词填空)

6 . In our school there are 50 students, half of __________ wear glasses. （用适当的词填空）

7 . Large numbers of people left the northern region __________ the war was continuing. （用适当的词填空）

8 . Last winter we went to visit the village ______ we were born and brought up. (用适当的词填空)

9 . He lives in a room _______ door faces south. (用适当的词填空)

10 . I’ll never forget the days ______ we lived together on the summer camp. (用适当的词填空)