请视原句：But few will be as sensible and considerate when making the long
journey of life <on board> a
big 'social' or 'global' train.请问该句中的词组 on board 后为何可直接跟名词？
Many of the animals were in prime condition and had more body fat than is customary for animals arriving from the wild.请问is customary for在此处是什么用法？感觉可以直接去掉？
The U.S. doesn't
even rank in thetop 40. But is also was included "because we live
here" and because of past, bold estimates that life expectancy in the U.S.
might surge dramatically in this century, Olshansky said.这句话的but is also有省略吗？感觉很怪，补全是怎么样的？
句1：Smart people are better able to admit when they don't know something.句中when引导的是什么从句？如果“when they don't know something”是时间状语从句，那么admit作为及物动词，后面没有宾语。如果“when they don't know something”是宾语从句，那么...
...n.外星人(生物)；外国人 adj.陌生的；外星的；外国的 pros and cons事物的利与弊；支持与反对 blurred /blɜːd/ adj.模糊不清的；难以区分的 superior /suːˈpɪəriə(r)；sjuː-/ adj.更好的；占优势的；(在级别或重要性上)更高的 superior to 比…...
...句，其中that通常可以省略。例如：I’m not going. How about you? 我不打算去。你呢？（摘自《牛津高阶英汉双解词典》第8版p.1025）How about a break ? 休息一下好吗？（同上）How about going for a meal ? 去吃饭好不好？（同上）How about your pare...
Vertebrate EPRS contains two distinct aminoacylation domains, connected by a non-catalytic linker, and first joined in a unicellular ancestor ~800 Mya.这里的connected与joined分别修饰什么，在句子是什么语法成分?
For me, it was the beginning of what would be more than half a decade of strategic avoidance and social discomfort.What would be作什么成分，能不能换成What was, 能不能省略？
temporal lobes and gray matter are very important brain areas.The brain areas are critical in the sense of....老师这是个改错题，答案是加上the，可不可以改为those，字典讲，都是特制刚说过的话，这样改有错吗？谢谢老师。
Before the reform and opening-up policy, Shenzhen was nothing but a small fishing village which has a population of over 30 thousand people.这里为什么用 which? 可以用 where 吗？
原文：And another mystery - some of these unrealistic animals - that's in the engravings - seem tobe half human.老师， that is in the engravings 这句话是some of these unrealistic&nb...