present perfect

present perfect present perfect simple and present perfect continuous 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 造句用 past simple and present perfect present perfect,simple past,请帮忙答题.