英语语法-从属分句.ppt

②在某些习惯用法中,多用as, 较少用which。如: as we/you know, as often happens, as may be imagined, as is well known, as if often the case, as is usual with sb., as is the custom with, as is natural, as is reported, as is shown in, as is hoped, as is supposed, as is anticipated, as has been said before, as has been pointed out, ect. 如: As a poet points out, life is but a dream. She has gone out for a walk, as may be imagined. ③as修饰整个主句，而which可修饰整个主句，或主句的一部分，或主句中的某一个名词或代词（先行词） ④as后若为被动语态，被动语态中的be动词可省略;which后的be动词在同样情况下则不可省略。如： Football and baseball, as(不用which)played in the United States today, are basically modifications of games that originated in England. ⑤as作主语时，还可用除be以外的其他系动词作谓语，一般不用行为动词;which则可用各类动词作谓语。如： He didn’t say anything at the meeting, as(which) seemed strange. He did much but said little, as(which) became his character. ⑥从功能上看，as引导的定语从句往往表示一种附加说明;which引导的定语从句则为较重要的评说。 真题举例及分析 例1 We’ve just installed two air-conditioners in our department, ___ should make great differences in our life next summer. (02) a. which b. what c. that d. they Key: a 考点：which引导的非限制性状语从句 例2 They overcame all the difficulties and completed the project two months ahead of time, __ is something we had not expected. (03) a. which b. it c. that d. what Key: a 考点：which引导的非限制性定语从句 例3 The physicist has made a discovery, _____ of great importance to the progress of science and technology. (97) a. I think which is b. that I think is c. which I think is d. which I think it is Key: c 考点：which引导的非限制性定语从句 例4 Firms that use computers have found that the number of staff ___ is needed for quality control can be substantially reduced. (2000) a. whose b. as c. what d. that Key: d 考点：that引导的限制性定语从句 例5 He is quite worn out from years of hard work. He is not the man _____ he was twenty years ago. (03) a. which b. that c. who d. whom Key: b 考点：that引导的限制性定语从句 关系代词that可以代指人或物，用作表语，仅限于限制性定语从句中，如：He i