be weak in=be weak at; be weak at后面通常只跟科目,如English,Chinese,math等;be weak in,除了跟科目,后面还可以跟某事,如be weak in running/spo...
have got 主语 + have not (havent) / has not (hasnt); have got Have / has + 主语 + got? have got 拥有,具有(美国英语的非正式语体中有时用got) ha...
结构can + 动词原形,没有人称和数的变化; 否定形式cannot/can’ t, cannot比缩略形式can’ t要正式。口语中一般用缩略形式; 例如 I can swim. 我会游泳。 D...