1. The facilities and skills of the teachers were probably well above average for the United States at that time. —— The facilities and skills of the teachers were perhaps much better than those in most schools in………學校的設施、教師的水平在當時的美國要遠遠高于平均水平。

well： adv. quite， rather

The work is well done. 這件工作干得很好。

It's well past midnight， I think it’s more time you went home.早過了午夜，我想你該回家了。

above/below average高于或低于一般標準或水平

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東西太多。

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.有時候， 我想那時要是能多學點真正重要的東西，那么今天我會多么地心存感激。

I would be ………if I had learned 虛擬語氣， 主句表示現在，從句表示過去

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？ 他能否通過考試是否很重要？

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路易斯安那購置

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.在一個約95%的居民不是美國人的星球上，學校當局認為只有美國歷史才值得講授。（此處作者也是委婉批評了美國教育部門的狹隘與偏見。）some： about； approximately

worth teaching——be worth doing值得做

6.Perhaps all the deficiencies have