(共30张PPT)
八年级英语下（JJ）
教学课件
Unit 7 Know Our World
Lesson 38: The World Is a Big Place
学习目标
Key words & phrases:
planet; total; increase; surface; Indian; in total; one third; be covered with; two thirds.
Key sentences:
1. These dry places are called deserts.
2. The Pacific Ocean is the largest one.
3. It must be treated well for our children and for our children’s children, too!
To learn about some geographical facts of the earth.
Words & Expressions
Let's read
planet
billion
total
increase
surface
Indian
n. 行星
n. 十亿；千兆
n. 总计；总数 adj. 总的；总计的
v. 增加；增大
n. 表面；表层
adj. 印度的 n. 印度人
Words & Expressions
Let's read
Atlantic
Arctic
in total
one third
be covered with
two thirds
n. 大西洋的
adv. 北极的
总计；合计；总共
三分之一
被……覆盖
三分之二
Let's enioy a song !
Warming-up
Lead in
How many continents are there in the world
What are they
Africa 非洲
亚洲:Asia
欧洲：Europe
北美洲 North America
南极洲：Antarctica
大洋洲：Oceania
南美洲 south America
What do you know about the place where you live
Free talk
Which continent does it belong to
What’s the population of your city
What’s the weather like
What’s the problem that your city faces
What’s your advice
How many continents and
oceans does the world have
Can you point them out
Presentation
The earth is a very special planet, and it faces a big problem. In the year 2010, the world’s population was over 7 billion in total. It is increasing very quickly. By 2025, the world may have about 8 billion people. And by 2050, the world’s population may reach 9 billion.
There is another problem. People can’t live everywhere on the earth. We can’t live in water, and only about one third of our planet is land. But parts of this land are very dry. These dry places are called deserts. Some areas have very high mountains. Others have a lot of snow and ice. It is not easy to live in those places.
There are seven continents: Asia, Africa, Australia, Antarctica, Europe, North America and South America. Antarctica is covered with snow and ice all year round. Luckily, people can live on the other six continents. On these continents, there are green forests, fresh water and rich lands.
Oceans cover two thirds of the earth's surface. The earth has only one big ocean, but we use these names for its different parts: the Pacific Ocean, the Indian Ocean, the Atlantic Ocean and the Arctic Ocean. The Pacific Ocean is the largest one.
The earth is our home now, and it will be our home in the future. It must be treated well for our children and for our children’s children, too!
Let’s Do It!
1. Read the lesson and match each paragraph with its main idea.
Paragraph 1 a. Six of the seven continents are good for people to live on.
Paragraph 2 b. We should treat the earth well.
Paragraph 3 c. An increasing population is a big problem for the earth.
Paragraph 4 d. Two thirds of the earth is covered with oceans.
Paragraph 5 e. People cannot live everywhere on the earth.
2. Fill in the blanks with the correct forms of the words in the box.
increase dry surface billion total
1. The number of swimmers here is __________ quickly because
it’s very hot these days.
2. The school has a ________ of 900 students.
3. I think it may be the ________ season of the year.
4. The ________ of our body is skin. It protects us.
5. How many ________ of people are there in the world now
increasing
total
driest
surface
billions
3. Match the seven continents with their correct descriptions.
Europe
South America
Asia
It is the biggest continent. It has the highest point on the earth in the Himalayas.
It is the sixth largest continent. It is a good place for people to travel to.
It is the fourth largest continent. There are 13 countries on this continent.
Africa
Australia
Antarctica
North America
It is the second largest continent. Many elephants, giraffes, zebras and lions live there.
It is the smallest continent. You can find koalas and kangaroos there.
It is the fifth largest continent. The South Pole is on this continent.
It is the third largest continent. Canada, Mexico and the U. S. are the three major countries on this continent.
Language points
1. The earth is a very special planet, and it faces a big problem（教材P100）
planet n.行星 为可数名词，指环绕恒星运转的星球。
e. g. The earth is the only planet that we know has life at present.
地球是目前我们所知的唯一有生命存在的行星。
2. In the year 2010, the world’s population was over 7 billion in total. （教材P100）
billion n. 十亿; 千兆
billion前有数词修饰时，billion不能用复数形式。
billions of意为“数十亿的”，表示不确定的数量。
e. g. We want two billion. 我们想要20 亿。
There are billions of stars in the sky. 天上有数十亿的星星。
total n. 总计; 总数 adj. 总的; 总计的
e. g. A total of twenty letters were received last month.
上个月共收到20 封信。
You can choose four out of the total number.
你可以从总数中选出四个。
The problem is how much the total payment is.
问题是要支付的总额是多少。
In total over 1, 000 people attended the conference.
共计一千多人参加了这个会议。
a total of修饰可数名词复数时，其谓语动词用复数形式；the total of... 后的谓语动词一般用单数形式。
in total意为“总计；合计”
adj .总的；总计的，一般在句中作定语，不作表语。
3. It is increasing very quickly.（教材P100）
increase v. 增加; 增大 也可作名词。反义词为decrease。常用短语on the increase “正在增加；不断增长”。
e. g. These cases are on the increase.
这些案件在不断增加。
His power increased. 他的权力加强了。
辨析：increase by 与increase to
① increase by ＋倍数或百分数，表示“增加了……倍或百分之……”。
② increase to＋具体增长后的数字，表示“增加到了……”
The population of this city has increased by 5 percent.
这个城市的人口增长了5%。
Our coal output has increased to 6 million tons this year.
我们今年的煤产量增加到了六百万吨。
4. We can’t live in water, and only about one third of our planet is land. （教材P100）
one third 三分之一
分数表达法: 分子用基数词, 分母用序数词。分子如果大于1, 分母用复数形式。
注意: 二分之一不能说a/one second, 而要说 a/one half; 四分之一和四分之三常用a quarter 和 three quarters 表示。
当“分数＋of+名词”结构作主语时，谓语动词的单复数取决于of后面的名词。名词为可数名词复数，谓语动词用复数；名词为不可数名词，谓语动词用单数。
e. g. Two thirds of the students in our class are girls.
我们班三分之二的学生是女生。
Three quarters of the information is true.
四分之三的信息是真实的。
5. Antarctica is covered with snow and ice all year round.（教材P100）
be covered with 被……覆盖
主动结构为：cover...with...(用……盖住……)
e. g. Our garden is covered with grass and flowers.
我们的花园被花草覆盖着。
Please cover this desk with a cloth.
请用一块布盖住这张课桌。
6. It must be treated well for our children and for our children’s children, too!
情态动词的被动语态
本句中 must be treated 是含情态动词的被动语态, 其结构为“情态动词(should, must, may, can, could 等) ＋ be ＋动词的过去分词”。
treat v. 对待; 看待 常用结构：
treat sb. as... 把某人看作……
treat/regard sb. with...以……对待某人
e. g. They treat the dog as a member of their family.
他们把狗视作家庭的一员。
She treats every child with kindness.
她用善心对待每个孩子。
Exercises
一、根据汉语或首字母提示，完成单词
1. The biggest ocean in the world is the P_______Ocean.
2. Almost everyone knows the e_____ goes around the sun.
3. Deserts may cover three _________ (百分比) of the earth’s surface.
4. The population of the world is __________ (增长) quickly.
5. Hainan is the second-largest _________ (岛屿) in China.
6. After half a month at sea, we saw ____(陆地).
land
acific
arth
percent
increasing
island
二、用适当的介词填空。
1. _____ 2025, the world will have 7.8 billion people.
2. Milk is good _________ children.
3. The Nile River is the longest river _________Africa.
4. Which part _________ the world do you live in
5. _________ the surface of the earth, there is some dry land.
On
By
for
in
of
Homework
Preview the passage in Lesson 39.
Do the exercises in students’ book.
Thank you!
