The present perfect simple is often used to talk about past actions and events which are completely finished.
一般现在完成时经常用于谈论过去的行为和事件其完全结束。
At first glance it looks as if there is no element of "present involvement" in this use of the present perfect any more than in the simple past.
乍看起来，在现在完成时的用法中，似乎跟在一般过去时中一样，都没有“涉及现在”的因素。
The English stative passive voice sentences can be the simple present, the simple past, the present perfect or the part perfect.
英语状态被动语态句型结构可以是一般现在时、一般过去时、现在完成时或者过去完成时。
Comparison Compare the difference between the simple past tense and the present perfect tense.
现在完成时与一般过去时所表示的动作或状态都发生在过去，区别…
Past simple or present perfect?
一般过去时还是现在完成时？
Past simple or present perfect?
一般过去时还是现在完成时？
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