根据句意，用括号中所给单词的正确形式填空。
1. They are trying to do something ______ (help) the old.
2. Sally prefers staying at home to ______ (go) out on Sundays.
3. How is your uncle? Please say hello to ______ (he) for me.
4. Nancy is too young to look after ______ (she). Don't leave her alone.
5. Recently the drought (干旱) is serious in the ______ (south) part of China.
6. Today most students can go to high school for further ______ (educate) in our country.
7. We're doing a lot of activities to celebrate the ______ (ninety) birthday of the Communist
Party of China (中 * * 党) this year.