高中英语外研版 (2019)选择性必修 第二册Unit 5 A delicate world课前预习课件ppt

这是一份高中英语外研版 (2019)选择性必修 第二册Unit 5 A delicate world课前预习课件ppt，共44页。PPT课件主要包含了Warming up，Actions，Purposes，Results等内容，欢迎下载使用。
Understanding ideasMACQUARIE ISLAND: frm Chas t CnservatinReading
Learning bjectives
At the end f the class, yu will be able t:1. find ut what happened t Macquarie Island2. make a flw chart t shw what human did, their purpses and the results and talk abut the effect f these human activities n Macquarie Island3. talk abut hw similar situatins culd be avided in the future
Starting ut
Watch a vide and answer the questins.
1. Are humans part f Earth’s ecsystems? Why? 2. In what ways can humans affect ecsystems?
1. Are humans part f Earth’s ecsystems? Why?
Yes. Humans are part f Earth’s ecsystems. It is because all the living things live in ecsystems and peple are living things.
2. In what ways can humans affect ecsystems?
Humans can affect ecsystems in psitive and negative ways. Fr example, t have a psitive influence n ecsystems, peple can plant trees, feed and prtect animals, recycle things, etc. Hwever, defrestatin, air and water pllutin and excessive waste affect ecsystems in a negative way.
1. Please lk at the picture and answer the questins.
1) What animals can yu see in the picture?2) What kind f changes wuld take place if cats, rats and rabbits were intrduced t an envirnment like this?
penguins and a seagull
2) What kind f changes wuld take place if cats, rats and rabbits were intrduced t an envirnment like this?
They wuld hunt the birds and eat the native vegetatin, thus upsetting the lcal eclgical balance.
Please lk at the title and make a predictin f the cntent.MACQUARIE ISLAND: frm Chas t Cnservatin
The passage may talk abut the chas and cnservatin f Macquarie Island.
Reading fr general idea
Please read the passage and find ut what happened t Macquaire Island.
Nn-native species were intrduced t Macquarie Island, which attacked native birds and led t a substantial reductin f bird ppulatin, and even the extinctin f parakeets. In additin, they ate and devastated the native vegetatin. All f this played a part in upsetting the natural harmny f the island. But nw the island’s eclgy is n the rad t recvery with human effrts.
Read the passage and find ut what each paragraph is abut, paying attentin t the imprtant wrds.
Paragraph 1 I am standing n Macquarie Island, in the Suth-west Pacific Ocean, halfway between Australia and Antarctica. Strng winds and strmy seas have helped sculpt its lng, thin shape. The green grass and bare rck f its landscape cntrast dramatically, giving it a wild and natural beauty.
N visitr wuld think it surprising that the island is a UNESCO Wrld Heritage Site. Nr wuld they fail t imagine hw its native inhabitants, including ryal penguins, king penguins, and elephant seals, existed in perfect harmny with their natural habitat fr thusands f years.
Paragraph 1 is an intrductin f psitin, shape, landscape, fame, and native inhabitants existing in perfect harmny f Macquaire Island.
Paragraph 2 But the island’s mre recent histry tells a different stry. It’s a tragic stry that began in 1810 when humans arrived n the island. In their ships they unknwingly brught rats and mice. These small animals quickly tk ver the island, eating the birds’ eggs and attacking baby birds. Cats were brught t the island t cntrl the rats and mice.
Unfrtunately, the cats subsequently develped an appetite fr the birds, t.
Paragraph 2 is an intrductin f the island’s mre recent histry — brught rats, mice and cats t the island. And the cats develped an appetite fr the birds.
Paragraph 3 Meanwhile, rabbits were intrduced t the island as a surce f fd fr humans. Lse n the island, they did what rabbits d best — they multiplied rapidly and began eating the native vegetatin and digging hles, which caused sil ersin. The explding rabbit ppulatin prvided plentiful fd fr the cats, meaning that the number f cats als increased. This in turn led t mre cats hunting the birds.
The end result was that parakeets, nce large in number and native t the island, died ut in1891.
Paragraph 3 is mainly abut: rabbits were causing sil ersin and the number f cats increased, resulting in the extinctin f the parakeets.
Paragraph 4 Even after Macquarie Island became an fficial nature reserve in the 1970s, the rabbits remained ut f cntrl. Experts felt it necessary t cme up with a plan t remve all the rabbits frm the island. With this gal in mind, a virus was released nt the island. But althugh the virus caused the rabbit ppulatin t decrease frm 130,000 t arund 10,000, it als meant less fd fr the cats.
The cats in cnsequence turned their attentin — and their stmachs — back t the native birds, killing up t 60,000 each year. In the 1980s, traps and dgs were used t catch the cats. The last Macquarie Island cat was caught in 2000.
Paragraph 4 is mainly abut the vicius circle (恶性循环): The rabbits remained ut f cntrl. A virus was released, causing the rabbit ppulatin t decrease. The cats killed mre birds. Traps and dgs were intrduced.
Paragraph 5 But as the saying ges, “While the cat’s away, the mice will play.” With the departure f the cats frm the island, the muse and rat ppulatin started t increase. And remember thse 10,000 r s rabbits? It turned ut that they develped an immunity t the virus, and their numbers explded nce again. Then in 2006, the rabbits’ digging caused sme land t cllapse, and killed a substantial number f penguins.
This incident made it clear that the rat, muse and rabbit prblem needed slving nce and fr all.
Paragraph 5 is abut the nging vicius circle: The muse and rat ppulatin started t increase. The number f rabbit explded, causing sme land t cllapse, and penguins killed.
Paragraph 6 S, I am here n Macquarie Island t participate in the prgramme t tackle this very prblem. The first step invlved pisn being drpped frm helicpters. The next step is t remve the last remaining invading species, and that’s where I cme in — with my dgs. They have been trained t find every last ne, withut harming the native animals.
This interventin is a lng, much-delayed ending t a sad stry, but we humans we it t the island t give it a happy ending.
Paragraph 6 is mainly abut the slutin t the prblem. Pisn was drpped and the invading species were remved t give Macquarie Island a happy ending.
Pstscript: In 2014, Macquarie Island was declared pest-free and the island’s eclgy is finally n the rad t recvery.
The pstscript intrduces the happy ending.
Think abut the relatinship f the paragraphs and find ut the writing style and structure f the text.An expsitry writingPara. 1: Intrductin f Macquarie IslandPara. 2—5: The chas caused n Macquarie IslandPara. 6: The cnservatin f the island
Please read the text mre carefully and make a flw chart t shw what human did t Macquarie Island, their purpses and the results n page 52.
Reading fr infrmatin
Human arrived n the island.
T live there.
Rats and mice were brught there by accident, and they tk ver the island, eating the birds’ eggs and attacking baby birds.
Cats were brught t the island.
T cntrl the rats and mice.
The cats develped an appetite fr the birds.
Rabbits wereintrduced t the island.
T prvidefd fr humans.
Rabbits multiplied and caused sil ersin. The explding rabbit ppulatin prvided fd fr the cats. This led t mre cats hunting the birds. Parakeets died ut in 1891.
A virus was releasednt the island.
T remve all the rabbits frm the island.
Substantial reductin f rabbit ppulatin led t cats killing mre native birds.
Traps and dgs were brught t the island.
T catch the cats.
The departure f cats resulted in an increasing ppulatin f rats and mice. And the rabbit ppulatin explded nce again.
Pisn and dgs were used.
T remve all the invading species.
The island was pest-free and its eclgy is n the rad t recvery.
Please talk abut hw human interference led t such severe cnsequences fr Macquarie Island by referring t the frm.
1. In 1810, human arrived n the island. Hwever, rats and mice were brught there by accident, and they tk ver the island, eating the birds’ eggs and attacking baby birds.2. Then, cats were brught t the island. But the cats develped an appetite fr the birds.
3. Rabbits were intrduced t the island. Rabbits multiplied and caused sil ersin. The explding rabbit ppulatin prvided fd fr the cats. This led t mre cats hunting the birds. As a result, parakeets died ut in 1891.4. A virus was released nt the island t remve all the rabbits frm the island. Substantial reductin f rabbit ppulatin led t cats killing mre native birds.
5. Traps and dgs were brught t the island t catch the cats. The departure f cats resulted in an increasing ppulatin f rats and mice. And the rabbit ppulatin explded nce again.6. Pisn and dgs were used t remve all the invading species. The island was pest-free and its eclgy is n the rad t recvery.
Reading fr pinins
Please read the passage again and chse the authr’s purpse in writing the passage and give yur reasns.
1) T analyse hw Macquarie Island was saved frm destructin.2) T infrm readers f the chas caused n Macquarie Island by humans.3) T entertain readers with a funny stry abut what happened n Macquarie Island.4) T suggest ways in which an ecsystem can be prtected.
Please think abut the fllwing questins and shw yur pinins:
1. D yu think it was right t eradicate the “pests” frm the island? Why?
2. Hw culd similar situatins be avided in the future?
Yes. The “pests” in the sentence refers t the invading species. T restre the eclgical balance, it was bvius that humans must eradicate the “pests”.
2. Hw culd similar situatins be avided in the future?
T avid similar situatins in the future, we shuld prtect the natural ecsystem and be aware f the ptential impact that human activities can have n ecsystems.
Thinking and sharing
1. What is yur understanding f “... we humans we it t the island t give it a happy ending”?2. What language can yu use t talk abut cause and effect? Hw wuld yu apply it t yur reading and writing?
It was humans that brught invading species t the island, breaking the balance f the island’s nature. S we humans we it t the island t give it a happy ending.
1. What is yur understanding f “... we humans we it t the island t give it a happy ending”?
2. What language can yu use t talk abut cause and effect? Hw wuld yu apply it t yur reading and writing?
In this lessn, we learned that when human arrived at Macquarie Island, they brught with them rats and mice by accident, which brke the eclgical balance f the island. What human did influenced the natural ecsystem. The lessn we learned is t avid similar situatins in the future and maintain the eclgical balance.