1 . Using cellphones while driving can often be seen, ________ is illegal in many countries. (用适当的词填空)

2 . ________ is announced on the school radio, the sports meet will be held next week. (用适当的词填空)

3 . ________ is often the case, some students play computer games so late that they can't finish their homework on time. (用适当的词填空)

4 . I would like to choose the student, __________ I think is the best, to be our monitor. (用适当的词填空)

5 . We must believe that we can succeed, __________ makes it possible for us to overcome the difficulties. (用适当的词填空)

6 . The couple, __________ life used to be very hard, have set up a series of chain stores in Europe. (用适当的词填空)

7 . My mother bought many children's books, nearly half of __________ were for my sister. (用适当的词填空)

10 . The manager, in ________ office I just attended an interview, asked me to go back home and wait for the reply. (用适当的词填空)