1. 用所给单词的适当形式填空。

1. （1） Simon (come) to see his Grandpa if he (be) free next week.

3. （2） We won't go to the mountains if it (rain) tomorrow.

5. （3） Let's (order) fruits from the shop.

7. （4） Half the students (be) 13 years old.

9. （5） Could you please give some (advice) to the teachers?