众所周知 ,由“助动词have(has) +过去分词”这种结构的现在完成时 ,它主要用于表示过去发生或已经完成的某一动作对现在造成的影响或结果 ,也可用于表示从过去已经开始 ,持续到现在的动作或状态 ,可以和表示从过去某一时刻延续到现在 (包括“现在”在内 )的一段时间状语连用。 It is known that when the structure of the “auxiliary has(has) + past participle” is now completed, it is mainly used to indicate the effect or result of an action that has occurred or has been completed in the past. It can also be used to indicate that it has been from the past. At the beginning, the action or state that continues until now can be used in conjunction with a certain adverbial phrase that represents a continuation from a certain moment in the past to the present (including “now”).