present perfect continous是什么

present perfect present perfect simple and present perfect continuous The present continous tense:现在进行时问题 present perfect;：indefinite past The present perfect tense present perfect tense,past perfect tense past continuous/present continuous/present perfect continuou 英语问题,求解释present perfect 和 present perfect continuous. 什么是PRESENT PERFECT CONTINUOUS啊? 请问present simple,the present continuous,the present perfect这 Present simple,present continuous,present perfect simple,pre present perfect 现在完成时?如果是 又用那些单词 句型是什么