用所给动词的适当形式填空
（1）Look, there are so many people over there. What (happen)?
（2）It's seven in the morning. It's time for us (go) to school.
（3）Look at the clouds in the sky. I think it (rain).
（4） (be) everyone here? Yes, Let's (start) now.
（5）He (be) be fifty years old next month. But he (look) so young.
（6）Teachers' Day (come) . And we (plan) to buy some flowers for Mrs. Li.
（7）My mother usually (shop) for food on Sundays.
