現(xiàn)在完成進(jìn)行時(shí), 這個(gè)時(shí)態(tài)可以用來(lái)描述一個(gè)在過(guò)去開(kāi)始但還在進(jìn)行的事情,或者是在現(xiàn)在有了結(jié)果,e.g. 'My legs ache because I've been running at the gym.'
如果我們說(shuō)的是 'How many times...?' 那么強(qiáng)調(diào)的是到講話時(shí)為止已經(jīng)完成的動(dòng)作,所以應(yīng)該使用現(xiàn)在完成時(shí),e.g. 'How many times have you missed class?'
你沒(méi)有選擇回答。
5
How long ___________ each other? We met when we were about 8 years old.
do we know
are we knowing
have we known
have we been knowing
The possible answers were:
do we know
are we knowing
have we known
have we been knowing