用所给单词的正确形式填空。
1. Uncle Li is repairing the broken watch to make it (use).
2. It's important to pay attention to the between English and Chinese. (different)
3. He needn't (coach) these kids for the coming football match.
4. It's a pity they put off (start) the museum.
5. (use) extra words helps to make language more polite.
1. useful
2. differences
3. coach
4. starting
5. Using