Part Ⅲ Grammar & WritingGrammar——名词性从句(Ⅱ):主语从句一、概念主语从句是在复合句中充当主语的句子,通常放在主句谓语动词之前或由形式主语 it代替,而本身放在句子末尾。二、基本用法1.连接词 that 和 whether(1)that 在从句中不充当任何句子成分,本身无任何意义,只起连接作用,但不可省略。That she survived the accident is a miracle.她在事故中幸免于难简直是奇迹。(2)whether 在从句中不充当任何句子成分,起连接作用,意为“是否”,不可省略。Whether we will build a new high school hasn't been decided.我们是否会建一所新的中学还没有定下来。Whether we go by train or by boat makes no difference.我们乘火车还是乘船没差别。2.连接代词(who, whose, whom, what, which, whichever, whoever, whomever, whatever 等)连接代词引导主语从句,在从句中可以作主语、宾语、表语或定语。Whoever did this job must be rewarded.无论谁做了这项工作一定要得到酬谢。Whatever you do in your spare time should do no harm to others.无论你在业余时间做什么都不应该伤害其他人。Whichever (of you) comes in first will receive a prize.无论(你们)谁先到都可以得奖。3.连接副词(when, where, how, why 等)连接副词引导主语从句并在从句中作状语。How this happened is not clear to anyone.这件事怎样发生的,谁也不清楚。Where we shall do the test is still under discussion.我们在什么地方做这个实验还在讨论。[关键点拨] 主语从句中连接词的选择技巧(1)根据连接词在从句中所作的语法成分。(2)根据连接词在从句中的意义。14.主语从句中用 it 作形式主语的结构(1)It+be+形容词(obvious, true, natural, strange, etc.)+主语从句It is important that he should know about this.他应该知道此事是重要的。[ 关 键 点 拨 ] 在 “ It + be + 形 容 词 + 主 语 从 句 ” 结 构 中 , 若 形 容 词为 important/necessary/strange 等,主语从句中的谓语用“(should) do”。(2)It+be+名词词组(no wonder, an honour, a pity, a/no surprise, etc.)+主语从句It's a pity that I can't attend your wedding.很遗憾我不能参加你的婚礼。(3)It+be+...