根据句意，用括号中所给单词的适当形式填空。
1. He'd like to buy a present for his sister's _______ (twelve) birthday.
2. We must pay attention to_______(tell) the differences between them.
3. David is the chairperson of the _______(student) Union.
4. We held the 29th Olympic Games _______(sucess)
5.You shouldn't worry about _______(not have ) breakfast.
6. How many _______(operate) do you perform every year?
7. I_______(stay) at home and sleep all day if there is no school tomorrow.
8. The man was badly hurt in the accident and he_______(send) to hospital immediately.
