题目内容：

用所给单词的适当形式填空（10分）

1.Mary ______ to do her homework. (have)

2.Monday is cold but Tuesday is _____ (cold) than Monday.

3.We have P.E. classes _________ (one) a week.

4.If you want to keep _____( health ), you'd better take more exercise and eat less food.

5.They _________(not have) any classes next week.