Unit 4

How Life Began on the Earth

theory atom

billion globe

violent carbon

atmosphere unlike

fundamental

n. 学说；理论n. 原子n. （英 ) 万亿； ( 美）十

亿n. 球体；地球仪；地球adj. 猛烈的；强暴的n. 碳n. 大气层；气氛prep. 不同；不像adj. 基本的；基础的

Words preview

harmfulacid

chain multiply

oxygen exist thus

dioxidecarbon dioxide

adj. 有害的n. 酸n. 链子；连锁；锁链vi. & vt. 乘；增加n. 氧vi. 存在；生存adv. 因此；于是n. 二氧化物 二氧化碳

Words preview

in time

lay eggs

give birth to

in one’s turn

prevent…from

及时；终于 下蛋 产生；分娩 轮到某人；接着 阻止；制止

Expressions preview

Skimming to get

general ideas

Skimming

Reading Comprehension I

1. Who knows how life began on the earth exactly? A. Scientists. B. Astronomers. C. No one. D. Aliens ( 外星人 ).2. What does “small clever animals” refer to? A. Insects. B. Reptiles. C. Dinosaurs. D. Humans.

Careful reading to solve

difficult points

1. in time 及时 ; 终于 in time (for sth/ to do sth)= not late

a. The car came to a stop just in time to

prevent an accident. 

汽车及时停下，避免了一场车祸。b. Can we get to the station in time? 

我们能及时到达车站吗？

2. laying eggs 下蛋 The hens are not laying well at the moment. 现在那些母鸡不爱下蛋。

lay, lie 区别lay vt (laid, laid, laying) 把东西放平 ; 下蛋 lie vi (lay, lain, lying) 平放

lie vi (lied, lied, lying) 撒谎

What prevented you from joining us last night? 昨晚什么事使你不能参加我们的晚会 ?

阻止某人做某事 :prevent sb. (from) doing sth. stop sb. (from) doing sth. keep sb. from doing sth.

3. prevent...from 阻止 ; 制止

We must prevent the disease (from) spreading.  我们一定要防止疾病蔓延。

Read the passage quickly to find the main idea of

each paragraph.

Read the passage carefully and analyse

its structure. Write down the main idea

for each paragraph.

Paragraph 1:

Paragraph 2:

Paragraph 3:

Paragraph 4:

Paragraph 5:

Paragraph 1: A widely accepted theory about the formation of the universeParagraph 2: The formation of the earthParagraph 3: The importance of water for lifeParagraph 4: The development of plants and animals on the earthParagraph 5: The arrival of humans and their impact on the earth

Scanning to get

detail information

1. The earth was different from the other planets in that__________. A. a cloud of dust was around the earth B. comfortable climate remained on the earth C. water remained on the earth D. carbon remained on the earth

scanning

Reading Comprehension II

2. The plants grew before the animals

because they provide__________.

A. nutrients for animals to absorb( 吸收 )

B. oxygen for animals to breathe

C. necessary temperature for animals

to keep warm

D. water vapour for animals

3. Which of the following statements is true?A. The dust settled into a solid globe between

4.5 and 3.6 billion year ago.B. The first small plants began to appear on

the surface of the land.C. About 2.6 million years ago some small

clever animals appeared and spread in the ocean.

D. Dinosaurs died out long before human beings developed on the earth.

Put the order of development of life intoa timeline. Use the reading passage to help you.

1 Insects and amphibians appeared.2 Dinosaurs appeared. 3 The earth became a solid ball.4 Small plants grew on the water.5 Reptiles appeared.6 Plants began to grow on dry land.

scanning

Reading Comprehension III

7 The earth was a cloud of dust.8 Water appeared on the earth.9 Shellfish and other fish appeared.10 The universe began with a “Big Bang”.11 Clever animals with hands and feet appeared.12 Mammals appeared.

Answer: 10 7 3 8 4 9 6 1 5 2 12 11

Detailed Reading

The development of the earth

Stage 1: The development of the earth

(1) After the Big Bang, what happened?

a cloud of dust a violent solid ball

exploded with fire and rock

produced water vapour and gases

(2) What happened next?

(3) What did the water vapour and gases form?

the earth’s atmosphere

Water appeared which is important for the beginning of life on the earth.

(4) What appeared on the earth then?

(5) What did the water form?

oceans and seas

1. Big Bang (a huge explosion around 15 billion years ago)

2. a cloud of energetic dust

3. a ball moving around the sun

4. exploded with fire and rock

5. produce the water vapour, carbon dioxide…

How did the earth come into being?

6. cooled down 7. water appeared

8. harmful gases were dissolved

The development of life

arrival of small plants in water

(1) What life developed after water appeared?

early shellfish

Stage 2: The development of life in water

all sorts of fish

(2) What life developed in water next?

green plants on land insects on land

(3) What life developed after the life in water?

amphibians on land and in the water forests

Stage 3: The development of life on land

(1) What life developed next on land?

reptiles on land dinosaurs on land

(2) What life developed after forests appeared?

mammals on land

(3) What life developed after dinosaurs?

small clever animals

(4) What life developed after mammals?

Can you say the sequence of development of life on the earth after detailed reading?

water water plantsshellfish

fish

land plantsland insectsamphibians

forests reptiles dinosaurs

mammalsclever animals

DM:

SC:

Read the passage again and underlineall the discourse markers (DM) and sentence connectors (SC).

however, after that, next, later,

finally, thus, as a result of this

and, but, because, or

Design an activity on Earth DayWhat is the activity is about?Why is the activity is designed?When and where is the activity? Who takes part in the activity?What is to be done in the activity?…

How can we protect the earth and make it a better place to live on?

Quiz

TranslationQuiz I 1. ____________________ ( 它会变成什么 ) was uncertain until between 4.5 and 3.8 billion years ago.2. It was not immediately obvious that ______________________________ _________________ ( 水会对生命的发展

起关键作用 ).3. ___________________________________ ( 为什么恐龙会突然灭绝 ) still remains a mystery.

What it was to become

water was to be fundamental to thedevelopment of life

Why the dinosaurs suddenly disappeared

1. ______ he referred to in his article was

unknown to the general reader.

（ 2007 上海卷）

A. That B. What

C. Whether D. Where

Quiz II

2. ______ parents say and do has a life-

long effect on their children.

（ 2007 陕西卷）

A. That B. Which

C. What D. As

3. It has been proved ____ eating

vegetables in childhood helps to

protect you against serious illnesses

in later life. (2008 上海卷 )

A. if B. because

C. when D. that

4. ______ we are sure about is the need

to prevent children from being spoiled.

(2008 上海春卷 )

A. What B. Which

C. Whether D. That

5. ______wants to stay in a hotel has to

pay their own way.

(2008 浙江卷 )

A. Anyone B. The one

C. Whoever D. Who

Homework

1. Search the Internet for

information of the development

of life and find more solutions

to global warming.

2. Finish the exercises on page 28.