Unit 5 Why do you do that?
A. Useful expressions:
1. cover…with sth be covered with sth
I will cover it with some soil. It will be covered with some soil by me.
2. stop v. end, prevent
stop+n./pron./sb(from)doing keep…from doing 阻止……做……
The policeman stopped the car.
We stopped the children from going out.
The rain kept us from going to the park.
3. break the rule(s) 違犯規則（章程）
It is not allowed to break the rules of the school.
類(lèi)似的用法還有：
obey the law 遵守法律 break the law犯（違）法
break one’s words(promise)違背諾言
work out a rule 制定規則 keep/follow the rule遵守規則
carry out a rule執行規則
4. grow up 成長(cháng)，長(cháng)大
What are you going to be when you grow up?
All plants like to grow up towards the sunlight
5. in the past 在過(guò)去
In the past , there were no trees left in or around the village.
Cf: in the past/last+ 具體時(shí)間
In the last 20 years, China has changed a lot.
B. Sentence patterns:
1. ways of expressing purposes
1)in order to （動(dòng)詞不定式）也可用so as to，或直接用動(dòng)詞不定式作目的狀語(yǔ)
注：用 in order to/so as to時(shí)， 主句謂語(yǔ)動(dòng)詞與動(dòng)詞不定式中動(dòng)詞的主語(yǔ)是一致的。
People had to walk many miles in order to fetch wood.
He got up early to come to school on time.
In order to/so as to否定式為： in order not to /so as not to
2) so that接從句，也可用 in order that
用so that /in order that時(shí)，從句的主語(yǔ)與主句的主語(yǔ)可以是不同的。
He turned up the radio so that everyone might hear the important news.
They are working hard so that they may pass the examination.
2． 被動(dòng)語(yǔ)態(tài)不同時(shí)態(tài)的表達
一般現在時(shí)：am/is/are+done Our classroom is cleaned every day.
現在進(jìn)行時(shí)：am/is/are+being+done The windows are being cleaned by the students.
現在完成時(shí)：have/has+been +done Has he been asked?
一般過(guò)去時(shí)：was/were+done His bike was stolen yesterday.
過(guò)去進(jìn)行時(shí)：was/were+being+done His bike was being mended yesterday afternoon.
過(guò)去完成時(shí)：had +been+done Clothes had been washed before my mother came back.
一般將來(lái)時(shí)：will/be going to+be+done Where will the big factory be built?
含有情態(tài)動(dòng)詞的:can/must/may/should+be+done A few of the trees can be cut each year.