Hoàn thành các câu sau bằng cách điền "enough" vào chỗ trống kèm theo các từ cho sẵn trong ngoặc.

1. She is not ____ (old) to drive a car.
2. This box is ____ (heavy) for me to lift.
3. The room is not ____ (big) for all of us.
4. He is ____ (intelligent) to solve the problem.
5. The water is not ____ (clean) to drink.