英语现在完成时定义 构成 用法及例句（不少于6句）

五、 现在完成时：

1.概念：过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。

2.时间状语：recently, lately, since…for…,in the past few years, etc.

3.基本结构：have/has + done

4.否定形式：have/has + not +d one.

5.一般疑问句：have或has。

6.例句：I've written an article.

It has been raining these days.
I have answered the quesion
The quesipn has been solved
Computer has been invited for many years
Have you been to the USA?
He has gone to home