为什么是 Be seen to do 而非 be saw to do?句子是：She was seen to come here.这是哪方面的语法问题啊?

为什么是 Be seen to do 而非 be saw to do?句子是：She was seen to come here.这是哪方面的语法问题啊? 为什么是remain to be seen 而不是remain to see不是 remain to do 为什么是be busy doing而不是be busy to do sb be seen to do sth 和 sb be seen do sth 有什么不同? To be born one day earlier,the baby could have seen his father.为什么是To be born呢? be seen to do和doing有神魔区别 be seen to do造句 10句以上啊 英语翻译sb be seen to do sth sb be seen to doing sth 这里要to吗 be seen 的用法比如说“他被看到在玩游戏”之类的,被动.be seen 什么时候用be seen doing?什么时候是be seen to do?什么时候是be seen do? see sb do/doing 被动用法sb be seen to do对还是sb be seen doing Whether it will do us harm remains_______A. seen B. seeing C. being seen D. to be seen 详细说明 关于be seen doing 和 be seen to do有 see sb doing 和 see sb to do,那么相应的,被动要还原to,是不是就改成sb be seen to doing 和 sb be seen to do?但好像没有sb be seen to doing 这种说法,只有sb be seen doing. 几个英语句子不懂、、、、I have never seen anyone run so fast——just watch David go这里的 just watch 是什么用法?I have nothing important on tonight.Do you have clothes to be taken to the laundry?这里 为什么是用 to be take see sb.do sth.的被动是be seen to do sth吗如题,还有有没有be seen do sth这种句式, Mary always has a lot of work to do为什么是to do 而不是被动式to be done? 为什么是there are something to do而不是to be done Do you have anything to be brought中为什么是被动?Do you have anything to be brought?Do you have anything to say?一个被动,一个主动. We haven't seen Jim for several days.What do you think has happened to him 为什么是has happened而不是will happen