用括号内所给单词的适当形式填空。
1. Two American (visit) will come to our school.
2. We'll learn the ____________ (twelve) unit next week.
3. Why are you so ____________ (forget) , Mike?
4. The yellow River is the second ___________(long) river in China.
5. I'm ____________ (true) sorry to hear that.
6. There are some children ____________ (play) football on the playground.
7. The ____________ (man) names are Li Ping、Wang Lin and Yang Li .
8. This book is mine. That one is____________ (they).
9. The cat wanted to be on the side of the ____________ (win).
10. Three (five) in our class are boys.