外研版 (2019)选择性必修 第二册Unit 5 A delicate world课文ppt课件

这是一份外研版 (2019)选择性必修 第二册Unit 5 A delicate world课文ppt课件，共23页。PPT课件主要包含了Part 1，BAD，Good，Part 2，TIMELINE，Homework，Part 3等内容，欢迎下载使用。
Starting ut
Understanding ideas
What is an ecsystem?
All the animals and plants in a particular area, and the way in which they are related t each ther and t their envirnment.
Are humans part f Earth’s ecsystems? Why?
In what ways can humans affect ecsystems?
Let’s enjy the vide!
1 What is happening t the area accrding t the satellite images?
2 What d yu think a later satellite image wuld shw?
3 What d yu think caused these changes?
The Aral Sea is shrinking because its water are being used fr irrigatin.
The Aral Sea was the wrld’s furth largest lake up until the third quarter f the 20th century. Hwever, in the 1960s, tw rivers, which used t be its main surces f water incme, were diverted s that they culd irrigate the desert in rder t favr agriculture. Althugh irrigatin helped develp agriculture, it destryed the Aral Sea.
1 What animals can yu see in the picture?
Read the passage, then answer the questin.
2 What kind f changes wuld take place if cats, rats and rabbits were intrduced t an envirnment like this?
Grup Discussin
What happened t Macquarie Island?
in the 1970s
in the 1980s
Chse the authr’s purpse in writing the passage and give yur reasns.T analyse hw Macquarie Island was saved frm destructin.T infrm readers f the chas caused n Macquarie Island by humans.T entertain readers with a funny stry abut what happened n Macquarie Island.T suggest ways in which an ecsystem can be prtected.
Read the passage again, then answer the questin.
Have a discussin in grups, rganize infrmatin frm the passage and cmplete the flw chart.
Cats were brught t the island.
Rabbits were intrduced t the island.
T prve fd fr humans.
A virus was released nt the island.
Traps and dgs were used.
Pisn and dgs were used.
T remve all the rabbits frm the island.
T catch the cats.
T remve all the remaining invading species.
The cats develped an appetite fr the birds.
Rats and mice were brught there by accident, and they tk ver the island, eating the birds’ eggs and attacking baby birds.
Rabbits multiplied and caused sil ersin, and the explding rabbit ppulatin prvided plentiful fd fr the cats. This led t mre cats hunting the birds. As a result, parakeets died ut in 1891.
The island was pest-free and its eclgy is n the rad t recvery.
The departure f the cats resulted in an increasing ppulatin f rats and mice. And the rabbit ppulatin explded nce again.
Substantial reductin f rabbit ppulatin led t cats killing mre native birds.
Talk but hw human interference led t such severe cnsequences fr Macquarie Island.