用所给词的适当形式填空。
1. Half the boys in my class ______ (like) playing basketball.
2. The mother asked his son ______ (not ride) too quickly on the way to school. It's dangerous.
3. If you exercise every day, you ______ (be) healthy.
4. What will happen if Lucy ______ (bring) her friends from other school to the party?
5. He is a difficult man ______ (communicate) with.