as可用作连词，引导比较、时间、原因及方式等四种状语从句，应注意的是，引导的比较状语从句往往有省略；引导的时间状语从句一般用一般现在时而不用一般将来时；引导原因状语从句时与“Because”和“since”引导的从句比较起起来语气最弱。 as作介词，意思时“作为”，“以……身份”。例如：He came to China as a tourist five years ago. 而表示像…一样时，like通常作介词用，而介词后面通常接名词，代名词和动名词。 as in Australia“和在澳大利亚一样”。 as……as AS +adj(原级)+AS AS +adv(原级)+AS as soon as 一……就 as soon as possible 尽可能快地 as early as possible 尽可能早的 as carefully as you can 尽可能认真地 as careful as you can 尽可能认真的 1。as是连词，表示“随着”的意义。lives是life的复数，意义是“生活”。
2。as是连词，表示“因为，由于”的意义。wanting是现在分词，表示主动意义，wanting to buy cars=who want to buy cars。 As的用法小结 as可以作连词、介词及关系代词和副词。现将其用法小结如下: （一）、 as作连词的用法: 1.作“在-------期间，当----的时候”引导时间状语从句.注意与when、 while的用法区别。 ①下列情形时,只用as, 而不用when或while。 1)用于表示同一个人的两种动作交替进行,指一边----一边. 如: The girl sings as she goes to school. He looked behind occasionally as he went forward in the forest. 2)表示两个同步发生的动作或行?意思是随着-----的发展.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)表示两个短暂行为或事情几乎同时发生.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)接在名词后面表示某一个年龄段时.如: As a young man, he was active in sports. ②when作"当……的时候"解,可以指较短的(一点)时间,也可指一段时间。如:When I was at college, I could speak several foreign languages. When the clock struck twelve, I had slept for 2hours. ③ while常表示一段较长的时间或一个过程,强调主句谓语动词与从句谓语动词同时发生。如:Work while you work. Play while you play. 2. As =Since 作"既然"、"由于"解,引导原因状语从句,常用来表示已为人们所知或显而易见的原因或理由。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,引导方式状语从句。如: Do as I told you. Remember, you must do everything as I do. 4. 用于as--- as或not / so/ as ---- as中,前一个as是副词,后一个as是连词,引导比较状语从句。如:They helped the old as much as possible. I don't speak English so/ as well as she does. 5. 表示虽然,尽管 等,引导让步状语从句,常用倒装语序,模式为: adj. /adv. / n.+as +主语+谓语+主句。如: Young as he is, he knows much. Tired as they were, they walked on. 6. 表示也------一样。 She is a doctor, as was her husband. （二）、 as作关系代词,引导定语从句,表示正如,这一点.如: He is very careful, as we all know. As is well-known, Taiwan belongs to China. 另外,当先行词被the same, such等词修饰时,常用as来引导定语从句。如: Such a clever girl as she can learn anything quickly. I was reading the same book as he bought yesterday. （三）、as作介词的用法. 1.表示好像。如:He dressed as a policeman. 2. 表示作为当作。如：I found a j