1. (2017七下·龙华期中) 根据句子意思，用所给单词适当形式填空。

1. （1） Because he worked hard, he was (success) at last.
3. （2） It took her a lot of time (encourage) the girl.
5. （3） My brother is good at(ski).
7. （4） Water is of great(valuable).
9. （5） How about (tick) the things that we need on the list?
11. （6） The school(lie) in the south of the town 30 years ago. It was destroyed in the war.
13. （7） We have done a lot of (experiment) so far.
15. （8） I forgot (lock) the door when I left home this morning. It's very dangerous.
17. （9） My sister (teach) me to skate when she was free.
19. （10） I give up (go) abroad to study because it will cost a lot.