人教版英语必修三Unit 4　Astronomy_ the science of the stars知识点课件36张

课件36张PPT。
Book 3　Unit 4　Astronomy: the science of the stars
1.harmful adj.有害的
教材原句
①What many scientists believe is that the continued presence of water al-lowed the earth to dissolve 　harmful????(harm) gases and acids into the o-ceans and seas.重点单词◆单句填空
②As far as I'm concerned, there is no harm 　in???? making an apolo-gy to him first.
③Her popular 1962 book Silent Spring raised awareness of the dangers of pollution and the 　harmful???? (harm) effects of chemicals on humans and on the world's lakes and oceans. (2016课标全国Ⅰ)◆一句多译
那时我意识到浪费时间玩电脑游戏对我的学习和健康是有害的。
Then I realized that wasting time in playing computer games
?点拨
(1)be harmful to/be bad for对……有害
(2)harm n. & vt.伤害;损害
do harm to sb.=do sb. harm对某人有害
There is no harm in doing sth.做某事没有坏处
(3)harmless adj.无害的2.exist vi.存在;生存
教材原句
①They laid eggs too and 　existed????(exist) on the earth for more than 140 million years. 它们也下蛋,并且在地球上存在了1亿4千多万年。◆单句填空
②Even though he is a little boy, strange ideas always exist　in???? his mind.
③The old lady became seriously ill last week;she has only existed　?on????
milk ever since.
④There　exists????(exist)a good way to solve the problem at present.
⑤Wang believes traditions should not be sealed in glass boxes at muse-ums. “That is only evidence that traditions once 　existed????(exist),” he said. (2018课标全国Ⅲ)◆完成句子
关于宇宙是如何产生的,科学家们有多种学说。
⑥Scientists have many theories about　how the universe came into existence??.点拨
(1)exist on靠……为生　　　exist in存在于……中
There exists/existed...有……;存在……
(2)come into existence产生;成立;开始存在
in existence存在
[点津]
exist是不及物动词,没有被动语态,也不用于进行时态。3.puzzle v.使迷惑;使为难;使困惑 n.谜;难题
教材原句
①How life began on earth is one of the biggest 　puzzles???? that scientists found hard to solve.地球上生命的起源是科学家们难以解决的最大疑惑之一。◆单句填空
②The researchers are still puzzling 　about/over???? how the accident could have happened.
③When the little girl was asked such a 　puzzling???? (puzzle) question, she stood there with a surprised look on her face.◆一句多译
所有的老师对他失败的原因困惑不解。
→④　All the teachers were puzzled about the reason for his failure.????(puzzled)
→⑤　What puzzled all the teachers was the reason for his failure.????(puz-zle v.;主语从句)点拨
(1)puzzle over/about sth.苦苦思索……
puzzle sth. out 琢磨出……的答案
(2)puzzled adj.迷惑不解的(常用来修饰人或人的表情)
puzzling adj.令人迷惑的(常用来修饰事物)1.in time 及时;终于;迟早;最后
教材原句
①They were 　in???? time to produce carbon dioxide,nitrogen,water vapour and other gases,which were to make the earth's atmosphere. 它们最终产生了二氧化碳、氮气、水蒸气和其他气体,从而形成了地球的大气层。重点短语◆写出下列各句中in time的含义
②Andy knew he could not reach the house in time.　及时????
③You'll succeed in time because you are always working hard.　迟早????
④Working hard made him successful in time.　最后????◆句型转换
The activity is so meaningful that we will never forget it.
→⑤　The activity is so meaningful that at no time will we forget it.????(用at no time改写)
◆完成句子
⑥Do you 　want to get up in time????(想及时起床) to have breakfast with your family, get in some exercise, or just be better prepared for your day?(2017课标全国Ⅲ)
点拨
in no time立刻;马上
at no time决不(放在句首时,句子用部分倒装)
at a time每次;依次
at one time曾经;一度
at the same time同时
from time to time有时;偶尔take one's time别着急;慢慢来
kill time消磨时间2.in one's turn 轮到某人
教材原句
①Thus they have, in 　their????(they) turn,become the most important ani-mals on the planet.◆单句填空
②People try to avoid public transportation delays by using their own cars, and this　in???? turn creates more problems.
③I think it's my turn　to drive???? (drive) the kids to school this week.
④It turned 　out???? that this young man was lazier than the old man's son.◆写作微练
⑤　When it was my turn, I was too excited to speak????.
当轮到我时,我激动得都说不出话来了。
◆句型转换
The party turned out to be a great success.
→⑥　It turned out that the party turned out to be a great success????(it作形式主语)
点拨
in turn 依次;轮流;转而;相应地
by turns 轮流地;交替地
take turns to do/(in)doing sth. 轮流做某事
It is one's turn to do sth. 轮到某人做某事了
It turns/turned out that...结果……3.cheer up (使)高兴;(使)振奋;感到高兴;感到振奋
教材原句
①I 　cheered????(cheer) up immediately and floated weightlessly around in our spaceship cabin watching the earth become smaller and the moon larg-er.◆单句填空
②Upon arriving at the classroom, the author was cheered　up???? by a warm welcome.
③They do this in order to encourage the crowds to cheer their sports team　on????.
◆单句改错
④When I'm feeling sad my mother tells me funny stories to cheer up.
????cheer后加me????点拨
(1)cheer sb. up使某人振作起来
cheer sb. on为某人加油
(2)Cheers干杯!
(3)cheering adj.鼓舞人心的
cheering news鼓舞人心的消息4.now that 既然
教材原句
①“Oh dear,”I cried, “walking does need a bit of practice 　?now that????
gravity has changed.” “天哪,”我大声说,“重力改变了,看来走路也的确需要练一练了。”◆完成句子
②It must have rained last night,　for the ground is wet????(因为地面是湿的).
③ 　Now that you know????(既然你知道 )why you want to wake up, con-sider re-arranging your morning activities. (2017课标全国Ⅲ)
◆写作微练
④既然我们制订了计划,我们就应该坚持执行。(2016浙江书面表达)
　Now that/Since we have made a plan, we should stick to it.????点拨1.倍数+as...as...
教材原句
①But when I tried to step forward, I found I was carried 　twice????(two)as far as on the earth and fell over.重点句型◆单句填空
②This book is twice 　thicker????(thick)than that one.
③The world's population has grown to more than six times 　what????it was in 1800.◆一句多译
最近发现的一颗行星几乎是地球的三倍大。
④A planet discovered recently is almost　three times as large as???? the earth.
⑤A planet discovered recently is almost　three times bigger than???? the earth.
⑥A planet discovered recently is almost 　three times the size of???? the earth.点拨
倍数的表达方式:
(1)倍数+as...as...
(2)倍数+比较级+than
(3)倍数+the size/height/length/width...+of...
(4)倍数+what从句2.make it+adj./n.+to do sth.
教材原句
①This produced a chain reaction,which made 　it???? possible for life to develop.◆单句改错
②The sun heats the earth, which makes it possible for plants grow.
　plants后加to????
③The government has already permitted the company to use special mate-
rials to make that easier for the vehicle to fly. (2017课标全国Ⅱ)
　that→it????◆一句多译
精通这项技术可能会让我们更加有效地利用网络。
④Mastering the technology　makes it possible for us to use the Internet more effectively????.
⑤Mastering the technology　makes it possible that we can use the Inter-net more effectively????.◆写作微练
⑥你最好定下规矩,每天都练习说普通话(Mandarin)。
　You had better make it a rule to practise speaking Mandarin every day.????
(make it a rule)点拨
在此结构中通常可用it作形式宾语,而把真正的宾语置于宾补之后。可用作宾补的词有名词、代词、形容词、不带to的动词不定式、过去分词、介词短语等。该结构变为被动语态时,不定式作主语的补足语要带
to。
[联想]
在该句型中,有时动词不定式结构可换为that引导的宾语从句。