题目内容：

C) 根据句子意思，用括号中所给动词的适当形式填空。

1.There are two policemen__________ (guard) at the gate of the building.

2.—Is your father a doctor?

—Yes, he is. He__________ (work) in the Children’s Hospital.

3.—I called you at 7 yesterday evening, but you were not at home.

—I__________ (have) dinner out with my friends at that time.

4.—Is this jacket yours, Linda?

—No. I think it__________ (belong) to Mary.

5.So far, Mr Brown and his wife__________ (teach) at our school for ten years.