Unit13 Healthy eating
1. Choosing what to eat is no longer as easy as it once was.
[答]作连词，表示比较。又如：My hometown is no longer the same as it was. 我的家乡同过去不一样了。
2. if we want to keep up with the high pace of modern life, we had better learn to make the right choices about what and how we eat. 如果我们要跟上现代生活的步伐，我们最好学会正确的选择吃什么以及怎么吃。
[答]这里if引导的是条件状语从句，we had better ...是主句，what and how we eat 是宾语从句做about的宾语。keep up with 赶上，跟上，had better最好。
1. Kwanzaa is a seven-day festival celebrating the culture and history of African Ameiricans. 宽扎文化节是美国黑人庆祝自己文化和历史的节日，前后持续七天。
[问]the culture and history of African Americans 是做celebrating的宾语吗?[答]是的。例如：Can you tell us why you want to stay here and what you will do when you stay here?你能告诉我你为什么要呆在这里及你想呆在这儿做什么吗?
2. The week following Christmas Day, many African -American families get together to greet the new year and think about the past.圣诞节之后的那个星期，许多美国黑人家庭聚集在一起相互问候新年并回忆过去。[问]to greet the new year and think about the past 是两个不定式短语作目的状语吗?[答]是的。请看下面两个例句：1、We could get there to have the meeting on time. 我们可以准时到哪儿开会。2、The boy said slowly to let me know clearly about what had happened. 哪个小孩讲得和年慢目的是让我对所发生的事情一目了然。
Unit15 The necklace
1. I'm sorry, but I don't think I know you.
[问]怎样翻译“I don't think I know you.?"
2. No, Jeanne, I wasn't ill. I know I look oler than my age now. That's because of hard work -ten years of hard work. 不，珍妮，我没有病，我知道我看起来比我的实际年龄要苍老多了。那都是因为艰苦劳动造成的——十年的艰苦劳动啊!
[问]beause of 与beause有什么区别?
[答]beause of是介词短语，后面接名词，代词或动名词。beause是连词，连接从句，表原因。例如：Beause he didn't work hard, he failed in his final examination. 由于他学习不刻苦努力，所以在期末考试中他失败了。
Unit16 Scientists at work
1. In the 18th century, Benjamin Franklin cinducted a number of experiments in which he showed what electricity is.在18世纪，本杰明富兰克林进行了许多次关于电的实验。
[问]...in which he showed what electrivity is. in + which 引导定语从句，修饰先行词experiments。 这里which不能由that替换。
(2)...what electricity is 宾语从句，做show的宾语。
(3)A number of...“许多，大量”，接可数名词复数，谓语要用复数形式;the number of...“……的数量”谓语动词应该用单数。
例如：A number of peasants are working inthe fields with the sun burning in the shy. 许多农民顶着烈日在地里耕作。
2. Having realized that I could use a kite to aftract lightning. I decided to do an experiment. 当我意思到能用风筝来接收闪电后，我决定做个实验。
[问]Having realized that ... 在句子充当什么成分?
[答]Having realized that ... 现在分词短语做时间状语。(=when I had realized that I could use a kite to attract lightning, ...)
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Unit17 Great women
That was a mean trick!那是卑鄙的伎俩!
The new order will mean working ov’ertime.新订单意味着加班加点。
l didn't mean to hurt you.我并不想伤害你。
means n.方式，方法meaning n.意义，意思，含义
meaningful adj.有目的的;有意义的用法拓展：mean sth./doing sth.意味着某事/做某事
mean to do打算做某事be meant to必须;得要
考题2 (典型例题)I _ you earlier but I had no time.
A. had meant to see B; meant to see C. had meant seeing D. meant seeing
考题2点拨：答案为A。首先应是mean to do句式表示打算/意欲做某事，所以排除c、D项，再者表示“本来打算早一些去看你”，所以用过去完成时表示过去未曾实现的想法。