用所给词的适当形式填空。
1. My hobby is reading comic books. What about _____ (you)?
2. Two _____ (five) of the students in our class are League members.
3. I don't think it's always right to be busy _____ (make) money all day.
4. He left home in a hurry because he had some problem _____ (solve) in his office.
5. I don't like travelling by plane. I think it's _____ (safe) to travel by train.