现在完成时的句子

1、He has turned off the light。他已把灯关了。

2、Have you found your pen yet?你已找到你的钢笔了吗?

3、He has lived here since 1978。自从1978年以来,他一直住在这儿。

4、I have been in the army for more than 5 years。我在部队已经呆了五年多了。

5、I have heard nothing from him up to now。到目前为止我没有他的任何消息。