英语选择性必修 第一册Unit 5 Revealing nature授课ppt课件

这是一份英语选择性必修 第一册Unit 5 Revealing nature授课ppt课件，共31页。PPT课件主要包含了目录页，Grammar，contents，had learnt，had lived，had hoped，had left，had spent，began，had led to等内容，欢迎下载使用。
Listening & speaking
Vcabulary building
a. Darwin suspected that the finches had evlved frm a cmmn ancestr …b. Many peple refused t believe that living things, including humans, had evlved frm lwer frms f life.
Grammar: Past perfect
Lk at the sentences frm the reading passage and answer the questins.
a. Darwin suspected that the finches had evlved frm a cmmn ancestr …
1. In sentence (a), which actin happened first, “suspected”r “evlved frm a cmmn ancestr”?
In sentence (a), “evlved frm a cmmn ancestr” happened first.
b. Many peple refused t believe that living things, including humans, had evlved frm lwer frms f life.
2. In sentence (b), which actin happened first, “refused tbelieve” r “evlved frm lwer frms f life”?
In sentence (b), “evlved frm lwer frms flife” happened first.
3. What des the structure had dne indicate?
It indicates the actin happened befre a certain past actin.
过去完成时的基本用法：1）表示在过去的某一时间或某一动作之前完成的动作或存在的状态，即“过去的过去”。例如：
a. 我们到达火车站之前，火车就已经离开了。 Befre we gt t the train statin, the train _____________. b. 我还没来得及说谢谢，他就跑开了。 Befre I culd say “thank yu”, he ____________.
had already left
had run away
2）表示从过去某一时间开始，一直延续到过去的另一个时间的动作，常用的时间状语有 by then, by the end f, by the time。例如：
a. 到上学期期末为止，我们已经学习了2000个英语单词了。 By the end f last term, we _________ 2000 English wrds. b. 到那时为止，他们已经在那里住了十年了。 They _________ there fr ten years by then.
3）表示愿望、打算等的动词，如 hpe, want, expect, think, mean, suppse, intend, plan等后接从句时，一般用过去完成时表示本打算实现而未实现的愿望和计划。例如：
a. 我本打算去机场接他，但是我有个重要的会议要参加。 I ____________ t meet him at the airprt, but I had an imprtant meeting t attend. b. 我原打算今年去度假，可是我离不开。 I __________ t take a hliday this year but I was nt able t get away.
had intended
4）在句型 hardly ... when 和 n sner … than 中，主句用过去完成时，从句用一般过去时，表示“一……就……”。例如：
a. 我刚离开就开始下雨了。 _______________ when it began t rain.b. 他刚坐下，电话铃就响了。 N sner ______________ than the telephne rang.
Hardly had I left
had he sat dwn
1. It was a yung man wh ________ medical schl withut cmpleting his degree. What’s mre, he ____________________ a letter frm his father predicting that he wuld be “a disgrace t yurself and all yur family”.
Nw lk fr mre sentences with the past perfect tense in the reading passage, and summarize its use in yur wn wrds.
had recently received
2. After Darwin __________ sme time in Suth America, his rm n the ship was crwded with samples f the plants and animals he _____________. 3. At that time, peple believed that all species ____________ n Earth at the same time, and _________________since. 4. It seemed their beaks ____________ accrding t what fd was available n that particular island.
had cllected
had appeared
had nt changed
Cmplete the paragraphs with the infrmatin frm the given sentences. The sentences are in the rder in which they happened. They can help yu t decide the use f tenses. 1. a Natural disasters led t fd shrtages in the 1960s. b Yuan Lngping began t d research n hybrid rice. c Yuan Lngping develped a better type f rice.
Cmplete the paragraphs with the infrmatin frm the given sentences. The sentences are in the rder in which they happened. They can help yu t decide the use f tenses.
Yuan Lngping 1 _______ t d research n hybrid rice because natural disasters 2 __________ fd shrtages in the 1960s. In the end, he 3 ___________ a better type f rice.
2. a Gregr Mendel chse t study pea plants because their characteristics were easy t cntrl. b Gregr Mendel made imprtant discveries abut genetics. c Gregr Mendel died in 1884.
Gregr Mendel 4 _________ study pea plants because their characteristics were easy t cntrl. By the time f his death in 1884, he 5 __________ imprtant discveries abut genetics.
Vcabulary building: Wrds & expressins abut clubs
Cmplete the nline encyclpaedia entry with the crrect frm f the wrds in the bx.
cmpete decline eat live intrducearrive
Lnesme GergeLnesme Gerge was thelast Pinta island trtise. He died in 2012. After Gerge’s death, the Pinta island trtise was declared extinct.
The extinctin f the Pinta island trtise is blamed n humans. Befre humans 1 ________ n the island, the species 2 _________ in islatin and 3 ______ the plants that naturally grew there. Gerge was discvered many years after their arrival, and by then humans 4 _____________ new species that 5 ___________ fr the fd the trtises ate. After gats in particular had been brught t the Island, the Pinta island trtise ppulatin 6 ________. Eventually, nly Gerge remained.
had intrduced
cmpete decline eat live intrduce arrive
Wrk in pairs. Act ut a rle-playusing the infrmatin in Activity 3.One f yu will play the keeper fLnesme Gerge, and the therwill play the reprter asking abutGerge. Use the past perfect tensewhere apprpriate.
Listening & speaking: Bidiversity
1. Bidiversity is imprtant.2. Bacteria are always harmful t humans.3. Sme species f bacteria are used in fd prductin.4. Many species f bacteria recycle dead rganic matter.5. Our immune systems are able t fight ff all germs.
Listen t the pdcast and chse the statements that are made.
Listening & speaking: While-listening
Cells• Every living thing is 1 ______________. They are like 2 ______________________________.• In the human bdy there are abut 3 _____________ human cells and arund 4 ________________bacteria cells.Bacteria• Mst bacteria in the human bdy can 5 ________________.• In the fd prductin prcess, bacteria can6 _______________ dead rganic matter.
help with digestin
thirty-nine trillin
thirty trillin
bricks that are used t build huses
made up f cells
Listening & speaking: After listening
D yu knw abut … ?By the way, …Actually, …Have yu heard f fact, …Speaking f which, …
D yu knw abut … ?Have yu heard f … ?
By the way, …Actually, …In fact, …Speaking f which, …
Checking backgrund knwledge
Adding infrmatin
Cmplete the bxes with the expressins frm the pdcast.
Listening & speaking: Reading
Read the passage and answer the questins.1. What species are mentined and what is special abut them?2. What ther unusual life frms d yu knw f?
1. What species are mentined and what is special abut them?2. What ther unusual life frms d yu knw f?
Tw species are mentined: the blue whale and the water bear. The blue whale is the largest animal species n Earth, which can grw up t almst 30 metres in length and weigh ver 130,000 kils. The water bear is prbably the tughest species, which can survive temperatures frm 150 ℃ t a belw freezing -272℃.
Vcabulary building
Cmplete the paragraphs with the crrect frm f the wrds and expressins in the bx.
The Galapags islands are renwned wrldwide fr their unique bidiversity. The Giant Trtise Reserve n Santa Cruz 1 _________ several species f giant trtise that 2 ____________ the Galapags islands.The island is als hme t the Charles Darwin Research Statin, where3 _________ studies are carried ut.
ancestrscientificbe native tprimitivehabitatappearancebe hme tecsystem
are native t
Mangrves are ne f the castal plantsthat grw n Isabela. They serve as the4 ________ fr varius birds and fish, and are very imprtant t the 5 _________.
Iguanas can be fund n San Cristbal. They have a very special 6 __________, with cmb-like spines n the back. There is evidence that all the different iguanas have develped frm mre 7 _________ nes and share a cmmn 8 _________.