Tea wasn't introduced into Europe until the early 17th century. And now it has _______ popular in Europe and America.这道题给的答案是become，请问可不可以用been呢？如果不行，为什么呢？
The brain is as active during REM (rapid eye movement) sleep - when most vivid dreams occur - as it is when fully awake.请问awake在这里是形容词还是副词呢，在这里是属于when从句的还是as从句的？如果awake是属于when从句的，那么as it is后面不缺成分吗？
...n be transported from long distances and stored until we need it, first in the supermarket, and then at home.这句话里的we can be transported的被动语态为什么要用在we上啊？不是应该用在packaged or canned food上吗？
句子：If you don’t like the drink you ordered just leave it and try a different one.在这个句子中，one 是指代 drink 吗？但问题是，drink 是不可数名词，那就是说 one 可以指代不可数名词，但这又是与语法书上的说法相违背的。这是为什么？
...rs from distant lands,friends of old you have been summoned here to answer the threat of Mordor. 翻译是：来自远方的陌生人，被召集至此对抗魔多威胁的老朋友。根据翻译，friends of old(老朋友）应该被定语从句修饰，但原句中的you 引导的句子不...
Greater demands were being placed on the police by growing violence and left and right-wing extremism. 不断增加的暴行和左翼右翼极端主义使得需要更多警力。老师：您好！这句话我没理解（1）为啥这里要用were being placed on 这个时态（2）我没理解这个...
Financial reports need not be publicly disclosed, as do the financial reports of publicly owned corpartions.这句话翻译为：“不像上市公司的财务报告必须公开”as do +.....翻译为“和...一样，像...一样”句子前半部分意为不用公开，但上市公司是要公开...
...s — Russia,Brazil,India and China — will become a much larger force in the world economy than widely expected,based on projections of demographic and economic growth,with China potentially overtaking Germany this decade.尊敬的老师请问，粗体字部分是作句子什么成份？是作主...
请分析句子成分，主要是逗号以后部分:It took him about ten minutes to make the trip each time, a delay sufficiently irritating that Obama’s assistant expended considerable effort to avoid it.
When the Revolutionary War was over, General Washington wanted to go home to his Virginia estate, called Mount Vernon.上文中过去分词called只表示被动但我没有看出来过去分词发生的时间在谓语动词之前？请老师讲解一下，非常感谢。（听曹老师讲解过，...
...的，请老师解惑，谢谢。例句，I would never have believed it. They have accepted the whole scheme.上文中的it是前照应，可是为什么与后面的整个句子照应，而不是与前面文章中的某物照应呢？（我认为前照应该是与前面的文章照应，而不应...