He looked behind occasionally as he went forward in the forest.
2)表示兩個同步發生的動作或行?意思是隨著-----的發展.如:
As time went on / by,she became more and more beautiful .
As children get older,they become more and more interested in everything.
3)表示兩個短暫行為或事情幾乎同時發生.如:I watched her as she read the book.
I thought of it just as you opened your mouth.
Just as the flying worm hit her face,she gave a loud cry.
4)接在名詞後面表示某一個年齡段時.如:
As a young man,he was active in sports.
②when作"當……的時候"解,可以指較短的(一點)時間,也可指一段時間.如:When I was at college,I could speak several foreign languages.When the clock struck twelve,I had slept for 2hours.
2.As =Since 作"既然"、"由於"解,引導原因狀語從句,常用來表示已為人們所知或顯而易見的原因或理由.如:As he’s been ill for ages,I will help him.
As / Since you"re not feeling well,you may stay at home.
As he wasn"t ready ,we went without him.
3.As =in the way that作"像"、"按照……的方式"解,引導方式狀語從句.如:
Do as I told you.
Remember,you must do everything as I do.
4.用於as--- as或not / so/ as ---- as中,前一個as是副詞,後一個as是連詞,引導比較狀語從句.如:They helped the old as much as possible.
I don"t speak English so/ as well as she does.
5.表示雖然,儘管 等,引導讓步狀語從句,常用倒裝語序,模式為:
adj./adv./ n.+as +主語+謂語+主句.如:Young as he is,he knows much.
Tired as they were,they walked on.
6.表示也------一樣.She is a doctor,as was her husband.
（二）、 as作關係代詞,引導定語從句,表示正如,這一點.如:
He is very careful,as we all know.
As is well-known,Taiwan belongs to China.
另外,當先行詞被the same,such等詞修飾時,常用as來引導定語從句.如:
Such a clever girl as she can learn anything quickly.
I was reading the same book as he bought yesterday.
（三）、as作介詞的用法.
1.表示好像.如:He dressed as a policeman.
2.表示作為當作.如：I found a job as a guide.
3.當某人是某身份時.如：As a child ,she was sent to abroad.
4.as引導的介詞短語大多用作狀語,as譯為"作為";少數情況可引起賓語補足語.如:
As a Party member,I"ll take the lead in everything.(狀語)
She works as a model.(狀語)
She has me as one of her best friends.(引起賓語補足語)
（四）、作副詞的用法 1 表示與------等同.如：This dress is twice as expensive as that one.2 像,如等.如：As before,he remained unmoved.
as可用作連詞,引導比較、時間、原因及方式等四種狀語從句,應注意的是,引導的比較狀語從句往往有省略；引導的時間狀語從句一般用一般現在時而不用一般將來時；引導原因狀語從句時與“Because”和“since”引導的從句比較起起來語氣最弱.
as作介詞,意思時“作為”,“以……身份”.例如：He came to China as a tourist five years ago.
而表示像…一樣時,like通常作介詞用,而介詞後面通常接名詞,代名詞和動名詞.
as in Australia“和在澳洲一樣”.
as……as
AS +adj(原級)+AS
AS +adv(原級)+AS
as soon as 一……就
as soon as possible 儘可能快地
as early as possible 儘可能早的
as carefully as you can 儘可能認真地
as careful as you can 儘可能認真的
1.as是連詞,表示“隨著”的意義.lives是life的複數,意義是“生活”.
2.as是連詞,表示“因為,由於”的意義.wanting是現在分詞,表示主動意義,wanting to buy cars=who want to buy cars.
As的用法小結
as可以作連詞、介詞及關係代詞和副詞.現將其用法小結如下:
（一）、 as作連詞的用法:
1.作“在-------期間,當----的時候”引導時間狀語從句.注意與when、 while的用法區別.
①下列情形時,只用as,而不用when或while.
1)用於表示同一個人的兩種動作交替進行,指一邊----一邊.如:
The girl sings as she goes to school.
He looked behind occasionally as he went forward in the forest.
2)表示兩個同步發生的動作或行?意思是隨著-----的發展.如:
As time went on / by,she became more and more beautiful .
As children get older,they become more and more interested in everything.
3)表示兩個短暫行為或事情幾乎同時發生.如:I watched her as she read the book.
I thought of it just as you opened your mouth.
Just as the flying worm hit her face,she gave a loud cry.
4)接在名詞後面表示某一個年齡段時.如:
As a young man,he was active in sports.
②when作"當……的時候"解,可以指較短的(一點)時間,也可指一段時間.如:When I was at college,I could speak several foreign languages.When the clock struck twelve,I had slept for 2hours.
2.As =Since 作"既然"、"由於"解,引導原因狀語從句,常用來表示已為人們所知或顯而易見的原因或理由.如:As he’s been ill for ages,I will help him.
As / Since you"re not feeling well,you may stay at home.
As he wasn"t ready ,we went without him.
3.As =in the way that作"像"、"按照……的方式"解,引導方式狀語從句.如:
Do as I told you.
Remember,you must do everything as I do.
4.用於as--- as或not / so/ as ---- as中,前一個as是副詞,後一個as是連詞,引導比較狀語從句.如:They helped the old as much as possible.
I don"t speak English so/ as well as she does.
5.表示雖然,儘管 等,引導讓步狀語從句,常用倒裝語序,模式為:
adj./adv./ n.+as +主語+謂語+主句.如:Young as he is,he knows much.
Tired as they were,they walked on.
6.表示也------一樣.She is a doctor,as was her husband.
（二）、 as作關係代詞,引導定語從句,表示正如,這一點.如:
He is very careful,as we all know.
As is well-known,Taiwan belongs to China.
另外,當先行詞被the same,such等詞修飾時,常用as來引導定語從句.如:
Such a clever girl as she can learn anything quickly.
I was reading the same book as he bought yesterday.
（三）、as作介詞的用法.
1.表示好像.如:He dressed as a policeman.
2.表示作為當作.如：I found a job as a guide.
3.當某人是某身份時.如：As a child ,she was sent to abroad.
4.as引導的介詞短語大多用作狀語,as譯為"作為";少數情況可引起賓語補足語.如:
As a Party member,I"ll take the lead in everything.(狀語)
She works as a model.(狀語)
She has me as one of her best friends.(引起賓語補足語)
（四）、作副詞的用法 1 表示與------等同.如：This dress is twice as expensive as that one.2 像,如等.如：As before,he remained unmoved.