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

这是一份外研版 (2019)选择性必修 第二册Unit 5 A delicate world优秀课件ppt，共22页。PPT课件主要包含了Aral Sea，virus，kill，catch，immunity等内容，欢迎下载使用。

X2U5 A delicate wrld Starting Out
Hw much d yu knw abut the Aral Sea?
situates in Central Asia, between Kazakhstan t the nrth and Uzbekistan t the suth;the river Syr Darya and Amu Darya flw int the Aral Sea;used t be the furth largest lake (1960s) and cntained 10 grammes f salt per litre;
Lk at the satellite images and answer the questins.
Activity 1 Lk and answer
1. What is happening t the area accrding t the satellite images?
2. What d yu think a later satellite image wuld shw? Why?
3. What d yu think caused these changes?
The water area is becming smaller and smaller/shrinking.
The water area will be smaller.
Perhaps the changes were caused by climate change, the irrigatin prject, the vegetatin damage etc.
human explitatin 开发，剥削
Activity 2 Watch and answer
Humans are part f Earth’s ecsystems. Because all the living things live in ecsystems and peple are living things.
human explitatin
1. What rle d humans play in the ecsystems and why?
A wnderful serenity has taken pssess
tundra /'tʌndrə/ 冻原
grassland 温带草原（接近苔原）
steppe 温带草原（树少的）
taiga /'taɪɡə/ 北方针叶林
prairie /ˈpreəri/ 北美草原
intertidal zne潮间带
savannah /sə'vænə/稀树草原
desert /ˈdezət/
subtidal zne潮下带
Supplementary materials
cntinental shelf 大陆架
trpical rain frests
deep cean znes
Artic ice packs 北极浮冰
estuary /ˈestjuəri/ 港湾
temperate rain frests
marine mud flat海洋泥滩
deciduus frests落叶森林
2. In what ways can humans affect ecsystems?
Psitive: peple can plant trees, feed and prtect animals, recycle things and s n.Negative: peple may cause defrestatin, air and water pllutin, excessive waste and s n.
Let’s explre mre abut the human impact n the ecsystem!
X2U5 A delicate wrld Understanding Ideas Macquarie Island: frm chas t cnservatin
1. What animals can yu see in the picture? Birds and penguins.2. What kind f changes wuld take place if cats, rats and rabbits were intrduced t an envirnment like this?the native vegetatin might be eaten;the lcal eclgical balance might be destryed;...
Activity 1 Lk and answer
Lk at the pictures and answer the questins.
Hw Macquarie Island was saved frm destructin.
Activity 2 Read and check
1. What kind f changes had taken place when cats, rats and rabbits were intrduced t an envirnment like this?2. What’s the main idea f the passage?
Read the passage quickly and answer the questins.
the birds were hunted; the native vegetatin was eaten; the lcal eclgical balance was destryed...
MACQUARIE ISLAND: frm Chas t Cnservatin
Activity 3 Read and answer
1. Frm what aspects des the writer intrduce the island in para.1?
Read the passage again and answer the fllwing questins.
2. What happened t the island then t make it a tragic stry?
Cats were brught t the island.
they tk ver the island, eating the birds’ eggs and attacking baby birds
The cats develped an appetite fr the birds.
Rabbits were intrduced t the island.
T prvide fd fr humans.
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.
3. Hw did peple react t the chas?
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.
Substantial reductin f rabbit ppulatin led t cats killing mre native birds.
The departure f the cats resulted in an increasing ppulatin f rats and mice. And the rabbit ppulatin explded nce again.
The island is pest-free and its eclgy is n the rad t recvery.
Pstscript: In 2014, Macquarie Island was declared pest-free and the island’s eclgy is finally n the rad t recvery.
Activity 4 Draw and present
Wrk in grups t draw a mindmap n what happened t Macquarie Island and present yur ideas.
ADD YOUR TITLE HERE
______ n the island and __________ brught
develp an _______
Activity 5 Read and chse
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.
单击此处可编辑内容，根据您的需要自由拉伸文本框大小
1. D yu think it was right t eradicate(消灭) the “pests” frm the Macquarie Island? Give yur reasns.2. Hw culd similar situatins be avided in the future?
Activity 6 Think and share
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.
Humans brke the _______ f the ________
Humans tried t _________ the _______
It is humans that have damaged the ecsystem f the Macquarie island and it is humans’ duty t help it return t nrmal.