“试管婴儿”技术在生物学上依据的原理是(    )。

A．有性生殖

B．无性生殖

C．克隆技术

D．基因工程

根据汉语提示完成句子。

1.They sat on the river__________________________(沉默).

2. There are many trees __________________(在……前面) my house.

3. The flood ___________(毁灭)the village.

4. They take part in everyday____________ (活动).

5. When I went into the room , she___________________________(正在给某人打电话).