PeriodThreeGrammar,Speaking&Writing1
主语从句的引导词类别例词说明从属连词that,whether两者在从句中均不作成分,只起连接作用;that无实义,whether表示“是否”
连接代词who,what,which,whoever,whatever等在从句中作主语、宾语、表语、定语等成分
连接副词when,where,how,why等在从句中作时间、地点、方式、原因状语等成分
Whatweneedismorewater
(连接代词what在从句中作need的宾语)我们需要的是更多的水
Whetherwecanliveontheearthdependsonwhethertheproblemissolved
(whether虽不作成分,但有“是否”的意思)我们能否在地球上生存就取决于这个问题能否得以解决
即时跟踪1选择适当的引导词填空(1)Whowilldoitdoesn’tmatter
(2)Whatwecannotgetseemsbetterthanwhatwehavehad
(3)Itshouldbeconsideredwhereyoucomefrom
(4)Whytheboyaskedmoneyfromhisclassmatessurprisedhisteacher
(5)WhetherI’llgoshoppingtodaydependsonwhetherIamfree
it作形式主语为保持句子平衡,常把主语从句后置,而用形式主语it代替
it作形式主语时常用于以下句型:句型说明It+系动词+形容词+主语从句常用于此句型的形容词有important,(un)likely,possible,necessary,natural,wrong等
It+系动词+名词+主语从句常用于此句型的名词有fact,idea,honour,quest