根据句意及汉语提示填空。

1.If  I have a _____ (机会), I believe I will do better next time.

2.All  the football players must _____ (遵守) the football rules.

3.It's very nice of you, but I can_____ (对付) the box myself.

4.Dr. White _____ (发明) kind of new medicine last year.

5.One of my teammates fell ill, so he can't_____ (训练)with us now.