well： adv. quite， rather

　　The work is well done. 这件工作干得很好。

　　It's well past midnight， I think it’s more time you went home.早过了午夜，我想你该回家了。

　　above/below average高于或低于一般标准或水平

　　2. ………how much I don't yet know. ——how much I don’t know up till now.我至今依然不了解的东西太多。

　　yet： at this point in time

　　3.Sometimes I think how grateful I would be today if I had learned more back then about what really matters.——I would be grateful today if I had learned more at high school about things that are really important.有时候， 我想那时要是能多学点真正重要的东西，那么今天我会多么地心存感激。

　　I would be ………if I had learned 虚拟语气， 主句表示现在，从句表示过去

　　I would not be so sleepy if I had slept well last night.

　　back then： back in my high school days

　　what really matters： what is important matter is used as a verb——

　　eg： Does it matter much whether he will not pass the exams？ 他能否通过考试是否很重要？

　　4.in some respects……； the only thing I ever heard in school about Napoleon was that the U.S made the Louisiana Purchase from him.

　　In some respects在某些方面；in respect of就某方面

　　Louisiana Purchase路易斯安那购置

　　5.On a planet where some 95% of the inhabitants are not Americans， the only history that was thought worth teaching was American history.——The population of the US accounts for only about 5% of that of the world. But in my high school days taught American history only because it was thought that the history of other countries was not important for Americans to learn.在一个约95%的居民不是美国人的星球上，学校当局认为只有美国历史才值得讲授。（此处作者也是委婉批评了美国教育部门的狭隘与偏见。）some： about； approximately

　　worth teaching——be worth doing值得做

　　6.Perhaps all the deficiencies have

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