求助一句英语句子的语法it's believed by many people to have been gradually from AD200 to AD500.这是我们英语课本上的一句句子 to have been 这里的to 跟哪个单词 covered over by sandstorms 这里的 over 是什么用法?

求助一句英语句子的语法it's believed by many people to have been gradually from AD200 to AD500.这是我们英语课本上的一句句子 to have been 这里的to 跟哪个单词 covered over by sandstorms 这里的 over 是什么用法? 一句英语句子语法It's farther from Ann Arbor than Detroit is.请问为什么末尾要有个“is”. 求教一句英语句子的语法What significance is there in gaining the world if it means losing yourself 求助英语句子结构问题“It is convenient as,A should be……”.as逗号后面是一句子,这个句子是否合乎语法,怎么正确地理解as意思和作用,逗号后面的句子就是一个简单句，用来描述A的。这是在看论 求助一个英语句子的语法分析It (ground underfoot) absorbs most of the water it contains from rivers.后面的 it contains from rivers 是什么语法现象? 求助英语句子结构“what's love got to do with it?, 一句英语的语法理解in one's twenties or something 和 in one's twenties的区别 求助一句英语正确写法某某的世界,例如维多利亚的世界.应该是Victoria's world还是Victorias' world~ It's time 的语法 英语改写句子,五年级.It's lunch time.(改同义句）(1)It's time____ ____.(2)It's time____ ____lunch.急,快点,要精准的. 问一英语句子how gentleman do it 这句英语在句子结构语法上对吗?如果不对,说明理由.它和 how do gentlemado it 有什么区别 这句句子语法有没有问题?Go and get your coat.It's there you left it. 一句英语句子的语法问题The teacher asked the excited children not to excited .从语法角度上来解释为什么不用 exciting. It’s business ,it is personal.这句子语法对吗 because it's Friday.Helen's happy变成It's Friday so Helen's happy .句子中SO的用法 是英语当中的什么语法点 麻烦知道的老师解析下 （求助）连词组句,要求句子通顺,语法正确teacher,parents,Tom's,be,English,of(.)animals,you,what,like(?) 请分析一个英语句子的语法结构friends 里的一句台词：What's an intellegent girl who wants to be in fashion doing making coffe?我知道此句的意思,只是不清楚语法结构,尤其是“making coffe”充当的是什么成份 英语翻译1.He has had several jobs since he graduated form Yale.2.He has had several jobs since he was a student at Yale.为什么语法书上解释说这两个句子的意思是相近的.同样下面一句It's two weeks since I was ill.语法书