Period Three Grammar—Noun clause：predicative clause感知以下课文原句，补全方框下的小题以上4个句子中的黑体部分都是从句，这些从句在词性上相当于一个名词，故被称作名词性从句，而且从句作表语，所以又被称作表语从句。
一、名词性从句1．概念：在主从复合句中，相当于名词的从句被称为名词性从句。
2．分类：名词性从句包括：主语从句、宾语从句、表语从句和同位语从句。
3．连接词4.注意事项(1)名词性从句要用陈述语序；(2)主从句的时态要基本呼应，有时需用虚拟语气；(3)注意某些连接词的特殊用法(见后)。
二、表语从句1．概念：在主从复合句中充当表语的从句，叫作表语从句。
它常位于系动词之后，用来说明主语是什么或怎么样。
2．连接词的用法(1)that引导的表语从句用法：①无意义②不充当成分③不可省略The trouble is that she has lost his address.麻烦的是她弄丢了他的地址。
My suggestion is that we should tell him.我的建议是我们应该告诉他。
(2)whether引导的表语从句The question remains whether they will be able to help us.问题还是他们能否帮我们。
[名师点津]if不能引导表语从句。
(3)连接代词和连接副词引导的表语从句The problem is how we can find him.问题是我们如何找到他。
He is no longer what he was.他已经不再是以前的他了。
That’s where you are wrong.那就是你不对的地方。
(4)because，as if/as though等引导的表语从句It sounds as if someone is knocking at the door.听起来好像有人在敲门。
That’s because you can’t appreciate music.那是因为你不会欣赏音乐。
3．注意事项(1)why和because引导的表语从句的区别I didn’t phone her，and that’s why she got angry with me.(强调“没打电话”这一结果)我没有给她打电话。
那就是她对我生气的原因。
I didn’t phone her，and that’s because I got angry with her.(强调“生气”这一原因)我没有给她打电话。
那是因为我生她的气了。
(2)表语从句中的虚拟语气在表语从句中，表示间接的命令、要求、请求、建议、决定等，主句中的主语通常是：advice，suggestion，proposal，request，order，idea等，从句谓语形式是“should＋动词原形”(should 可以省略，但不可换成would)。
My suggestion is that we (should) start early tomorrow.我的建议是我们明天一早就出发。
Ⅰ.补全句子1．The fact was that he didn’t really try.事实是他没有做真正的努力。
2．The question is whether the film is worth seeing.问题是这部电影是否值得看。
3．Now it seems as though/if she has known Millie for years.现在看起来好像她认识米莉已有好多年了。
4．My advice is that you (should) practise speaking English as often as possible.我的建议是你尽可能经常地练习说英语。
5．That’s where I first met her.那就是我第一次遇见她的地方。
6．The problem is who is really fit for the hard job.问题是谁才真正适合做这份艰苦的工作。
7．That is why I want you to work here.那就是我想让你在这儿工作的原因。
8．I was late for school this morning.That’s because I stayed up too late last night.今天早上我上学迟到了。
那是因为我昨晚睡得太晚了。
Ⅱ.语法填空(用适当的连接词填空)Everyone knew 9.that Wendy was a famous writer，but no one knew 10.where she came from and 11.whether she was born in 1961 was still a mystery.12.What they did know was 13.that she was loved by poor people because she always helped 14.whoever was in need of money.Wendy was generous and helpful，but some people thought she was chasing fame.Wendy said she didn’t understand 15.why they were so narrowminded，but it didn’t matter 16.what others thought ofher.She just wanted to do 17.what(ever) she thought was right.She thought that was 18.where the meaning of life lied.基础巩固Ⅰ.选用适当的连接词填空that；why；whether；what；as if；whatever；because；when；how1．You must do whatever is best for you.2．The trouble is that I lost the key to my room.3．I am not sure whether he is willing to help me.4．I’m a bit sleepy，it’s because I was up all night.5．Do you remember when/how/why he came here?6．I’m wondering why you are always late for class.7．We think that it’s necessary to talk with him again.8．The question discussed at the meeting was whether it was worth trying.9．All this was over twenty years ago，but it is as if it were only yesterday.10．My parents are very kind to me and always let me do what/whatever I think I should do.Ⅱ.完成句子11．That’s why I think(那就是我认为……的原因) the trip along the Yangtze River will be a better choice.12．And you also should keep it in mind that exchanging notes with your classmates frequently is a good way to improve your study(和同学经常交流笔记是提高学习的好方法)．13．All the participants can get what they want(他们想要的东西)．14．In such a case I will insist on whatever I think is right(我认为正确的任何事情)．15．To practice as much as possible is where the secret lies(秘密所在)．16．You need to hand in a report，explaining how the idea occurred to you(你怎样想到的这个主意) and what materials you used.17．I’m wondering whether/if you would like to spend this time with us(你是否愿意和我们度过这段时光)．能力提升Ⅲ.阅读理解APeople have been wondering why elephants do not develop cancer even though they have lifespans(寿命) that are similar to humans，living for around 50 to 70 years.Now scientists believe they know why.A team at the University of Chicago，US has found that elephants carry a large number of genes that stop tumors(肿瘤) developing.To be precise，they found 20 copies of an antitumor gene called TP53 in elephants.Most other species，including humans，only carry one copy.According to the research，the extra copies of the gene improved the animal’s sensitivity to DNA damage，which lets the cells quickly kill themselves when damaged before they can go on to form deadly tumors.“An increased risk of developing cancer has stood in the way of the evolution of large body sizes in many animals，” the study author Dr Vincent Lynch told The Guardian.If every living cell has the same chance of becoming cancerous(癌变的)，large creatures with a long lifespan like whales and elephants should have a greater risk of developing cancer than humans and mice.But across species，the risk of cancer does not show a connection with body mass.This phenomenon was found by Oxford University scientist Richard Peto in the 1970s and later named “Peto’s paradox(悖论)”．Biologists believe it results from larger animals using protection that many smaller animals do not.In the elephant’s case，the making of TP53 is nature’s way of keeping this species alive.The study also found that when the same genes were brought to life in mice，they had the same cancer resistance as elephants.This means researchers could use the discovery to develop new treatments that can help stop cancers spreading or even developing in the first place.“Nature has already figured out how to prevent cancer，” said Joshua Schiffman，a biologist at the School of Medicine，University of Utah，US.“It’s up to us to learn how different animals deal with the problem so that we can use those strategies to prevent cancer in people.”18．Why are elephants unlikely to develop cancer?A．They have a rather large body size.B．Their genes suffer no DNA damage.C．Certain genes in their body kill existing tumors.D．They carry many genes to prevent tumors developing.答案D解析细节理解题。