为什么They have come.come是原形而They have gone.gone就不是原形

为什么They have come.come是原形而They have gone.gone就不是原形 they have come bake to you now 为什么have后面加do的形式?不懂 英语翻译为什么要用have,不直接They come here on purpose to see you. they would have come to her help.译文：他们本来应该上去帮她的.此句是否存在语法错误?是不是应该用co have they come back yet意思 They are still discussing whether I_____to the meeting yesterday,which I think was not necessary at all.A.could come B.should have come C.should come D.must have come 选B.为什么?C为什么不行? Friend：they came home late.You：It was inconsiderate of them 《to have came》 home late.为什么不是to come They do not have to come.（改为同义句） They ___not come. they cant have come back from the exhibition show yet 反义疑问they cant have come back from the exhibition show yet,反义疑问要你选反义疑问,一个是have they 另一个是do they ,选哪个?为什么?如果是have they的话神恶魔时 come and have a look!you have great change!l believe you can walk farest!co First of all,they may have come to this planet of ours thousands or millions of years ago为什么用现在完成式have come to,后面不是有years ago.不用过去完成式had come to They have been trapped for sevevteen hours.They tried to come up hours( )问题补充中为选项A since B ago C for D since then 为什么 Tom with his parents_____to America.They _____back in two weeksA.have gone;will come Bhas gone;will come C have been;have come D have been;come 反义疑问句填空They must have come back,______? have been 和 have arrived用法上有什么区别They _____here for more than a month.A have arrived B have reached C have come D have been为什么选D而不选A呢 ———of them have come back yet,have they?A.None B.Nobody C.Each D.All请教选什么?为什么? 英语中come to end 和 came to end的区别They have already expressed a keen interest in working in design after their tennis careers come to end 这里为什么不用 came to end 而用 come to end if they come,we will have a meeting(改为同义句 if they come,we ()()()()a meeting