人教版高一英语必修三Unit 4课文翻译

人教版高一英语必修三

Unit 4

课文翻译

Unit 4 Astronomy:the science of the stars

—

Reading

—

HOW LIFE BEGAN ON THE EARTH

地球上生命的起源

No one knows exactly how the earth began, as it happened so long ago.

However, according to a widely accepted theory, the universe began with

a

to form and combine to create stars and other bodies.

没有人确切知道地 球是怎样开始形成的，

因为在很早很早以前它就形

成了。然而， 一种普通为人们所接受的理论是：宇宙起源于一次大爆

炸，这次大爆炸将物质投射到四面 八方。然后，原子开始形成并结合

成恒星和其他天体。

For several billion years after the

a cloud of dust. What it was to become was uncertain until between 4.5

and

3.8

billion

years

ago

when

the

dust

settled

into

a

solid globe.

The

earth

became

so violent that

it

was

not

clear

whether

the

shape

would

last or

not.

It

exploded

loudly

with

fire

and

rock.

They

were in

time to

produce carbon,

nitrogen,

water

vapour

and

other gases,

which

were

to

make the earth's atmosphere. What is even more important is that as the

earth cooled down, water began to appear on its surface.

大爆炸后好几十 亿年过去了，

但地球还只是一团尘埃。

随后它会

变成什么没人能知道，直到

38-45

亿年前，这团尘 埃才慢慢地形成一

个固体的球状物。地球

(

开始

)

变得激烈动荡，不知道这个固体形状是

否会继续存在下去。它

(

地球

)

猛烈的爆炸喷出了烈火与岩石。最终产

生了碳、氮气、水蒸 气和其他多种气体，从而形成了地球的大气层。

更为重要的是，地球冷却了下来，地球的 表面就开始出现了水。

Water

had

also

appeared

on

other planets

like

Mars

but, unlike the

earth, it had disappeared later. It was not immediately obvious that water

was

to be fundamental to

the

development

of life.

What

many

scientists

believe

is

that the

continued

presence

of

water allowed

the

earth

to

dissolve harmful gases and acids into the oceans and seas. This produced

a chain reaction, which made it possible for life to develop.

在火星这些其他行星上都出现了水，

但和地 球不同的是，

这些水

后来都消失了。

水 会对生命的发展起关键作用，

这一点在当时并不明

显。很多科学 家相信，由于地球表面上长期有水存在，它使得地球得

以把有害气体和酸性物质溶解在海 洋里。这就产生了一系列的反应，

使得生命就有可能开始发展了。

Many millions of years later, the first extremely small plants began

to appear

on

the

surface

of

the

water.

They multiplied and

filled

the

oceans and seas with oxygen, which encouraged the later development of

early shellfish and all sorts of fish. Next, green plants began to grow on

land.

They

were followed

in

time

by

land

animals.

Some were

insects.

Others,

called

amphibians, were

able

to

live

on

land

as

well

as

in the

water. Later when the plants grew into forests, reptiles appeared for the

first time. They produced young enerally by laying eggs. After that, some

huge

animals,

called

dinosaurs, developed.

They

laid

eggs

too

and existed on the earth for more than 140 million years. However, 65

million

years

ago

the

age

of

the

dinosaurs

ended.

Why

they

suddenly

disappeared still remains a mystery. This disappearance made possible the

rise of mammals on the earth. These animals were different from all life

forms

in

the

past,

because

they gave

birth

to young

baby

animals

and produced milk to feed them.

好几百万年以后，

水的表面开始出现了 极小的植物。

它们繁殖起

来就使得早期的海洋充满了氧气，

这为早期的贝类及其他各种鱼类的

发育进一步创造了条件。