Unit+5+Working+The+Land+Discovering+Useful+Structures+主语从句讲义-高中英语人教版选择性必修第一册.docx
Grammar主语从句一、主语从句的基本用法1、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。【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。2、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, question, pity等It+系动词+过去分词+主语从句常用于此句型的过去分词，有known, proved, said, decided, suggested, thought等It+不及物动词+主语从句常用于此句型的动词有appear, happen, seem, occur, matter等。【注意】（1）在“It+ be+过去分词+主语从句”结构中，过去分词若为suggested/ordered/required/advised等， 主语从句中的谓语用“(should）do”。(2）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”。二、主语从句中应注意的问题1、从句要用陈述语序2、主谓一致（1）从句作主语时，主句的谓语一般用单数形式。what 引导主语从句时，有时主句谓语动词应与主句中作表语的名词保持一致。(2)如果由and连接两个或两个以上的主语从句作主语时，谓语动词用复数；由两个或多个连接词 引导一个主语从句时，谓语动词用单数。:Part3 Writing课文重点句1.Indeed,his slim but strong body is just like that of millions of Chinese farmers, to whom he has devoted his life.（“介词+关系代词”引导定语从句）确实，他瘦削但结实的身躯看起来和他为之奉献了一生的千千万万的中国农民一样。2. Given that Yuan's hybrids have made him quite wealthy, one might think he would retire to a life of leisure.（given +that从句）考虑到杂交水稻已经使袁隆平变得相当富有，人们可能认为他会退休享受闲适的生活。3、 Yet, he considers himself a farmer because he continually works the land in his research.然而，他认为自己是个农民，因为他在不断地研究耕种土地。4、 Today, it is estimated that about 60 percent of domestic rice consumption in China is comprised of crops generated from Yuan's hybrid strains.据估算，现在中国国内消费的大米有大约百分之六十来自袁隆平的杂交水稻5、 Yuan's innovation has helped feed not just China, but many other countries that depend on rice as well.袁隆平的创新不仅帮助了中国，也帮助了许多其他依赖大米的国家。6、As for chemical fertilizers ,crops grown with them usually too fast to be grow rich in nutrition.至于化肥，用它们种植的作物通常生长得太快，无法提供丰富的营养。7、 What keeps them from doing so is the fact that chemical farming serves the high demand for food around the world.(同位语从句)阻止他们这样做的原因是化学农业满足了世界各地对粮食的巨大需求。 学科网（北京）股份有限公司
