文档介绍：He is very careful, as his work shows. As is well-known, Taiwan belongs to China. 三、 as 作介词的用法: as 引导的介词短语大多用作状语,as 译为" 作为"; 少数情况可引起宾语补足语。如: As a League member, I'll take the lead in everything. ( 状语) She works asa doctor. ( 状语) They have me as one of their own children.( 引起宾语补足语) as 还有一些固定结构: 1)as well as ———和……一样 2)as far as ———就……来说 3)as long as ———只要 4)as soon as ———一……就 5)as if ———好像 while 的用法连词 while 大致有以下四种用法: ,意为"当……的时候;和……同时",此时的主从句谓语动作同时发生,从句谓语通常是延续性动词。如: Mary watched TVwhile she ate her supper. 玛丽边吃饭边看电视。 While she was listening tothe radio, she fell asleep. 她听着收音机睡着。 whil e引导从句时,如主从句的主语一致,且从句谓语又含有be, 则从句主语和be 可省略。 while 后可直接跟现在分词、名词、形容词或介词短语。如: Weare teachers while (we are) serving asstudents. 我们边当老师边当学生。 While (he was) yet ayouth, hegained many prizes. 他年轻时就曾多次获奖。 Hecaught acold while(he was) onvacation. 他度假时患了感冒。 ,意为"而;然而"。此时,while 一般位于句中。如: Some people waste food while others haven't enough. 有些人浪费粮食,然而有些人却吃不饱。 You like sports, while Iprefer music. 你喜欢体育,而我更喜欢音乐。 ,通常位于句首,意为"尽管;虽然"。如: While Iagree with your reasons, Ican't allow it. 尽管我同意你的理由, 但我不能允许这样做。 While heloves his students, heisvery strict with them. 虽然他爱他的学生,可是他对学生们很严格。 While (he was) respected, heisnot liked. 他虽受人尊敬,但并不被人喜欢。 ,意为"只要",其意思和用法相当于 aslong as。while 可位于句首, 也可位于句中。如: You don't have toworry while weare here. 只要我们在,你就别着急。 There will belife while there iswater and air.