1. 用所给词的正确形式填空

1. （1） Jack finds it difficult to pronounce some English words (correct).

3. （2） Tom thinks people will help him if he asks for help (polite).

5. （3） It's fun (play) football.

7. （4） China is one of the countries with the (long) history.

9. （5） The boy is old enough to (dress) himself.

11. （6） The weather in Beijing is quite (difference) from that in Guangzhou.