happen to have done sth 和pretend to have done sth 的中文意思

happen to 与happen to have done 的区别是什么? happen to have done sth 和pretend to have done sth 的中文意思 happen to 未发生 happen to be doing 正在发生 happen to hhappen to 未发生happen to be doing 正在发生happen to have done 已发生是这样区别的吗?老师说是.有点不确定 happen to dohappen to be doing happen to have done翻译下,还有没有其他的词语也能这样用,这种用法叫什么名字,再多举些例子 have done to have been done 和 to be done 帮忙运用英语根据下面词语各造一句子ever since in order to because of such as happen to devote to could have done how often should ought to have done were to have done 造句, be believed to have done were able to have done should have done 可以换成 ought to have done嘛? have something done 与have sth.to be done 区别 pretend have done还是pretend to have done? have sth to be done/have sth done?为什么要用have anyting to be done? the accident was supposed _____due to careless driving A to happen B .to have happened可是was supposed to have done 是过去本应该发生却没有发生? Ought to have done .must have done.should have done的区别 seem to do seem to have done