九年級英語The green consumer教案
because, since, as和for引導的原因狀語從句
1. because(因為)：表示直接的原因或理由，著重點在從句，用于回答why，語氣最強。
he didn’t go to school because he was ill.
why didn’t he go to school?
because he was ill.
2. since(既然)：一般表示對方已知的，無須加以說明的既成事實的理由，全句中心在主句，語氣比because弱。
since you are ill, i’ll go alone.
3. as(由于)：表示十分明顯的原因，一般說明因果關系，著重點在主句，語氣較弱。
as it is snowing, we shall not go to the park.
4. for(因為，其理由是）：是個并列連詞，只能放在另一個并列句后面，表示推理或解釋，或用作附加說明，表示新的情況，而不是指理由或原因，語氣最弱，一般不放在句首。
the day breaks, for the birds are singing.
* for表示因果關系時，可以同because交替使用，但for前須用逗號，而because則不必。
you couldn’t have seen him because he wasn’t there.
= you couldn’t have seen him, for he wasn’t there.
*當原因是顯而易見的或已為人們所知，就用as或since，且多放在句首。
since/ as the weather is so bad, we have to delay our journey.
as…as的基本用法
用于比較句型，中間插入的是形容詞或副詞的原級。意思是“達到與什么相同的程度”。如：he is as strong as a horse. 他力大如牛。
幾個習慣用法：
1. as soon as
引導一個時間狀語從句:
i’ll call you as soon as i finish my homework.
我一完成我的作業，就給你打電話。
2. as long as
she has searched the information about dinosaurs on the internet as long as three hours.
她在因特網上搜索有關恐龍的信息已經長達三個小時。
3. as much as
some of the stones weigh as much as fifteen tons.有些石頭重達15噸。
the same as的用法：
the same as：和……一樣。
例如：his dream is the same as mine.他的夢想和我的一樣。
the same to：一般用習語：the same to you!（在別人向自己祝福后，用這句話給別人同樣的祝福）。
the same with：適合于……。
例如：my thought are also same with mary.我的想法對mary也適用。
different from 和 different than 英語和美語中都經常見。
當直接對兩人或兩物進行比較時，from 是最保險的選擇：
my book is different from (not than ) yours.
但different than 的比較對象用一完整的句子表示，特別是在美語用法中，這種用法更能接受：
the campus is different than it was 20 years ago.
校園和二十年前不一樣了。
the campus is different from how it was 20 years ago.
校園和二十年前的樣子不一樣了。
（二）寫作練習：如何解決環境污染問題
24 april
director
shanghai environment bureau
dear sir/ madam
i am writing to inform you about three problems that are causing damage to our environment.
the first problem is an air problem. it occurs on bird street. it is caused by a factory building. a lot of unpleasant smoke comes out of the building’s chimney. its effect is to pollute the area and make everything smell unpleasant.