20.too many太多，后接可数名词复数。too much太多，后跟不可数名词，修饰动词作状语。
much too太，后跟形容词或副词，分辨三者的口诀：too much,much too,用法区别看后头:much后接不可数,too后修饰形或副。too many要记住，后面名词必复数。
21.because of因为,后接名词、代词或动名词(即动词+ing)，不能接句子。
because因为，后跟句子。
He was late for school because of getting up late.他因为起晚而上学迟到。(get为动词)
=He was late for school because he got up late.
22.enough(足够的)与名词连用，一般放在名词前He has enough money.
23.enough(足够的)与形容词或副词连用，enough放在后面。He is old enough to go to school.
24.doing sth.忘记已经做过某事(已经做完)
Forget to do sth.忘记去做某事(还未做)(forget的过去式为forgot)
25.so+形容词+that+句子：如此…以至于…
too+形容词+to do sth：太…以至于不能…
形容词+enough to do sth：足够…能够做某事(注意三个句型有时可以互换)
He is so young that he can′t go to school.=He is too young to go to school.=He isn′t old enough to go to school.
Unit 2 How often do yoexercise?
本单元的短语和知识点：
1.on weekends在周末go to the movies去看电影help with housework帮助做家务how often多久一次hardly ever几乎从不
2.once a week每周一次twice a week每周两次every day每天use the Internet用互联网
3.be free有空Are yofree on weekends?你周末有空吗?
4.stay up late熬夜at least至少go to bed early早点睡觉play sports进行体育活动
5.after school放学后6.want sth：需要某物He wants a new pen.他想要一支新钢笔。
want to do sth:想做某事He wants to watch TV after school.放学后他想去看电视。
want sb to do sth:让某人做某事My mother wants me get up early.妈妈让我早起。
7.be good for对……有好处be bad for对……有害处
8.play computer games打电子游戏go camping去野营
9.ask sb about sth：问某人某事My parents often ask me about my study.我的父母经常问我的学习情况。
10.in one's spare time在某人业余时间He studies English in his spare time.
11.(P13，2b)”数字+percent of+名词”做主语时，后面的单词取决于名词的情况。若名词为复数，后面的动词用复数形式;若名词为单数或不可数名词，后面的动词用单数形式。
In our class,twenty of students are boys.Thirty of water is dirty.
12.not…at all:一点儿也不(not构成否定句)I don't like the movie at all.
