你认为酶的合成场所是什么？需要什么原料？

用Be 动词的适当形式填空。

1. Jack ______ late for school yesterday, for he ______ ill.

2. I ______ in the same school as Ted last year.

3. The windows of the office ______ not open yesterday.

4. How old are you going to ______ next year?

5. Let's ______ good friends, shall we?

6. There ______ a lot of flowers in the garden last summer.

7. We ______ often hungry after a long trip.

8. The leaves ______ green in spring.

9. The weather tomorrow will ______ fine.

10. The wind last night ______ very strong.