资源简介

(共18张PPT)
Unit7 The natural world
Reading 1
1.Master the pronunciation and meaning of key words such as ecosystem, pollution, and oxygen.
2.Be able to grasp the main idea of the passage by skimming and extract key information by scanning.
3.Be able to discuss and express ideas related to ecosystems in English.
Learning objectives
Can you share some fun facts about ecosystems
Revision
How many ecosystems are there in the video
Lead in
They are Oceans Wetlands and Forests
Let's explore the three magic lands of the Earth—oceans, wetlands and forests.
What do you know about oaceans,wetlands and forests
The big three:
oceans,wetlands and forests
An ecosystem includes all the living and non-living things in an area.Ecosystems can be of different sizes,from small ponds to large grasslands.Each ecosystem has a role to play and helps keep the balance between all its members and the greater environment.
The ocean is a very large ecosystemon earth.It covers around71%of theearth's surface and produces about 70% of the earth's oxygen.It holds plenty of salt water,and the water rises to the sky,falls onto the land and then returns to
the ocean.This goes on and on,so the ocean is just like the“heart”of the Earth.
Wetlands only cover about 6%of the earth's land area.But they are home to about 40%of the world's plants and animals.Plants in wetlands help get rid of pollution and make the water clean. Wetlands can also help prevent floods.During heavy rains,wetlands store water like giant sponges.They act like the "kidneys"of the earth.
Forests make up nearly a third of the earth's land area.Plants there take in carbon dioxide from the air and produce oxygen.They also trap harmful things in their leaves and help clean the air. Therefore,people often call forests the "lungs"of the earth.
Each of these ecosystems supports millions of plants and
animals.They keep the planet healthy and make our world a better place.
Read the text and complete the following tasks.
Task1
What is an ecosystem
An ecosystem includes all the
(plants, animals, microorganisms) and_______________ (water, air, soil, sunlight) in an area, and they work together to keep balance.
living things
non-living things
Task2
What are the three main ecosystems mentioned
What are their nicknames
The three main ecosystems mentioned are oceans, wetlands, and forests.
Oceans are nicknamed the "heart" of the earth.
Wetlands are nicknamed the "kidneys" of the earth.
Forests are nicknamed the "lungs" of the earth.
Task3
How big are they What can they do for the Earth
Oceans
The largest ecosystem on Earth, covering 71% of the planet's surface.
Forests
Large areas dominated by trees, covering nearly one-third of Earth's land.
Wetlands
Unique ecosystems where water covers the soil for all or part of the year.
Task4
Reading for the structure(结构).
An ecosystem includes all the living and non-living things in an area. Ecosystems can be of different sizes, from small ponds to large grasslands. Each ecosystem has a role to play and helps keep the balance between all its members and the greater environment.
The ocean is a very large ecosystem on earth. It covers around 71% of the earth’s surface and produces about 70% of the earth’s oxygen. It holds plenty of salt water, and the water rises to the sky, falls onto the lands and then returns to the ocean. This goes on and on, so the ocean is just like the “heart” of the earth.
Wetlands only cover about 6% of the earth’s land area. But they are home to about 40% of all the types of plants and animals. Plants in wetlands help get rid of pollution and make the water clean. Wetlands can also help prevent floods. During heavy rains, wetlands store water like huge sponges. They act like the “kidneys” of the earth.
Forests make up nearly a third of the earth’s land area. Plants there take in carbon dioxide from the air and produce oxygen.They also trap harmful things in their leaves and help clean the air. Therefore, people often call forests the “lungs” of the earth.
Each of these ecosystems supports millions of plants and animals. They keep the planet healthy and make our world a better place.
What is an ecosystem
What are the main ecosystems
How important are the ecosystems
Careful reading
C. Ecosystems Sustain Life
B. What is an Ecosystem
A. Forests: Earth’s Lungs
E. Wetlands: Earth’s Kidneys
D. The Ocean: Earth’s Heart
Match the main ideas with paragraphs
A. Look at the picture and choose the correct descriptions for each ecosystem according to the article. Write the correct letters in the boxes.
a Cover 71% of the earth’s surface
b Cover nearly a third of the earth’s land area
c Help clean the water
d Help make the air clean
e Help prevent floods
f Produce about 70% of the earth’s oxygen
g The “heart” of the earth
h The “lungs” of the earth
i The “kidneys” of the earth
a f g
- a: “covers around 71% of the earth’s surface” P2
- f: “produces about 70% of the earth’s oxygen” P2
- g: “the ocean is just like the ‘heart’ of the earth” P2
c e i
- c: “Plants in wetlands help get rid of pollution and make the water clean” P3
- e: “wetlands can also help prevent floods” P3
- i: “They act like the 'kidneys' of the earth” P3
b d h
- b: “Forests make up nearly a third of the earth’s land area” P4
- d: “Plants there... help clean the air” P4
- h: “people often call forests the ‘lungs’ of the earth” P4
Careful reading
Careful reading
An ecosystem includes all the living and non-living things in an area. Ecosystems can be of different sizes, from small ponds to large grasslands. Each ecosystem has a role to play and helps keep the balance between all its members and the greater environment.
1. What is an ecosystem made up of
a Oceans, wetlands and forests.
b Plants and animals.
c Living and non-living things.
Read para.1 and choose
Careful reading
Read para.2 and choose
2. Why is the ocean the largest ecosystem of the three
a It holds plenty of the earth’s water.
b It makes up about 71%of the earth’s surface.
c It is home to many kinds of plants and animals
The ocean is a very large ecosystem on earth. It covers around 71% of the earth’s surface and produces about 70% of the earth’s oxygen. It holds plenty of salt water, and the water rises to the sky, falls onto the lands and then returns to the ocean. This goes on and on, so the ocean is just like the “heart” of the earth.
Careful reading
Read para.3 and choose
3. What do wetlands do during heavy rains
a They make the water clean.
b They hold water.
c They get rid of water.
Wetlands only cover about 6% of the earth’s land area. But they are home to about 40% of all the types of plants and animals. Plants in wetlands help get rid of pollution and make the water clean. Wetlands can also help prevent floods. During heavy rains, wetlands store water like huge sponges. They act like the “kidneys” of the earth.
Careful reading
4. “They also trap harmful things in their leaves and help clean the air.” Which word can we use to replace the word “trap”
a keep b drive c produce
Read para.4 and choose
Forests make up nearly a third of the earth’s land area. Plants there take in carbon dioxide from the air and produce oxygen.They also trap harmful things in their leaves and help clean the air. Therefore, people often call forests the “lungs” of the earth.
5. Where can we read this kind of article
a In a newspaper
b In a travel guide.
c In a geography magazine.
1.Why are the three ecosystems important for the earth
2.What are some of the non-living things in an ecosystem Are they important
Give reasons.
3.How do human activities affect the ecosystems Give an example.
Human activities can both harm and protect ecosystems.For example, people throw plastic waste into oceans, which poisons marine animals like turtles and fish.
The three ecosystems (oceans, wetlands, forests) are vital for the earth because they work together to maintain ecological balance.
Common non-living things in an ecosystem include water, air, soil, sunlight, and temperature. They are extremely important. Water and air are necessary for all living things to survive.
D Think about the questions below. Share your answers with your classmates.
Careful reading
Homework
C1.reate ecosystem function matching cards. 2.
Match oceans/wetlands/forests to their organ metaphors using text quotes.

展开更多......

收起↑