Unit 2 Topic 2 Section C
课文讲解及知识点
一 . 课文翻译 :
The earth is 4.6 billion years old .
地球已有46亿年的历史。
We humans have lived on the earth for only 35000 years , but during this period , we have changed our planet a lot in many ways .
而我们人类仅在地球上生活了35000年,但在此期间,我们以多种方式极大地改变了我们的星球。
Some things we have done are very good for the earth while others are bad .
我们所做的一些事情对地球非常有益,而另一些则是有害的。
All over the world , people have cut down millions of trees .
全世界的人们砍伐了数百万棵树木。
When it rains or when the wind blows , the earth is taken away .
当下雨或刮风时,土壤被冲走。
Forests have become deserts , so many kinds of animals and plants are disappearing .
森林变成了沙漠,许多种类的动植物正在消失。
In big cities , cars and buses have polluted the air .
在大城市中,汽车和公共汽车污染了空气。
Now many people in cities have health problems .
现在,许多城市居民都患有健康问题。
Factories have also polluted the land and the water .
工厂也污染了土地和水源。
As a result , many rivers and lakes are now dead .
结果,许多河流和湖泊现在已经死寂。
Around the earth , there ' s a special kind of oxygen called " ozone "( O ,).
在地球周围,有一种特殊的氧气叫做“臭氧”(O )。
It is important to the earth .
它对地球很重要。
But now air pollution is destroying it and making a very big hole in the ozone layer .
但现在空气污染正在破坏它,并在臭氧层中形成了一个非常大的空洞。
Too much harmful radiation from the sun passes through the hole and reaches the earth directly .
太多的有害辐射从太阳穿过这个空洞直接到达地球。
This is very dangerous because this kind of radiation can cause cancer .
这是非常危险的,因为这种辐射会导致癌症。
Carbon dioxide (CO2) in the air has increased a lot .
空气中的二氧化碳(CO )含量大幅增加。
It mainly comes from burning oil , coal and wood .
它主要来自石油、煤炭和木材的燃烧。
This has formed a blanket around the earth .
这已经在地球周围形成了一层毯子。
The heat from the sun can ' t escape so the temperature is rising .
来自太阳的热量无法逃逸,因此温度正在上升。
This is called " the greenhouse effect ".
这被称为“温室效应”。
It causes the level of the oceans to rise and the climate of the earth to change .
它导致海平面上升和地球气候发生变化。
All these problems are very serious , so we must do something now .
所有这些问题都非常严重,所以我们现在必须采取行动。
二 . 课文讲解及知识点:
The earth is 4.6 billion years old.
主语:The earth
系动词:is
表语:4.6 billion years old
知识点:
“billion”表示十亿。
“years old”用于描述年龄或存在时间。
短语及拓展:
“be + 数字 + years old”结构用于表示年龄或持续时间。
拓展短语:“millions of years ago”表示数百万年前。
We humans have lived on the earth for only 35000 years , but during this period , we have changed our planet a lot in many ways .
主语:We humans
谓语:have lived
状语:on the earth, for only 35000 years
并列句:but during this period, we have changed our planet a lot in many ways
主语:we
谓语:have changed
宾语:our planet
状语:a lot, in many ways
知识点:
“during this period”表示“在这个时期”。
“in many ways”表示“在许多方面”。
短语及拓展:
“live on”表示“居住,以...为食”。
拓展短语:“in a way”表示“在某种程度上”,“change...a lot”表示“大大改变”。
Some things we have done are very good for the earth while others are bad.
主语:Some things
定语:we have done
谓语:are
表语:very good for the earth
并列句:while others are bad
主语:others
谓语:are
表语:bad
知识点:
“while”引导并列句,表示对比。
“be good/bad for”表示“对...有好处/坏处”。
短语及拓展:
“do good/bad to”也表示“对...有好处/坏处”。
拓展短语:“on the one hand...on the other hand”表示“一方面...另一方面”。
All over the world , people have cut down millions of trees .
状语:All over the world
主语:people
谓语:have cut down
宾语:millions of trees
知识点:
“All over the world”表示“全世界”。
“cut down”表示“砍倒”。
短语及拓展:
拓展短语:“cut off”表示“切断”,“cut up”表示“切碎”。
When it rains or when the wind blows , the earth is taken away .
时间状语从句:When it rains or when the wind blows
主句:the earth is taken away
知识点:
“when”引导时间状语从句。
“or”表示选择关系。
短语及拓展:
拓展短语:“as soon as”也表示“一...就...”。
Forests have become deserts , so many kinds of animals and plants are disappearing .
主句:Forests have become deserts
结果状语从句:so many kinds of animals and plants are disappearing
知识点:
“so”引导结果状语从句。
“disappearing”是现在分词作表语,表示状态。
短语及拓展:
拓展短语:“as a result”也表示“结果”。
In big cities , cars and buses have polluted the air .
状语:In big cities
主语:cars and buses
谓语:have polluted
宾语:the air
知识点:
“In big cities”表示地点状语。
“have polluted”是现在完成时,表示过去的动作对现在的影响。
短语及拓展:
拓展短语:“in the city”表示“在城市里”。
Now many people in cities have health problems .
时间状语:Now
主语:many people in cities
谓语:have
宾语:health problems
知识点:
“Now”表示现在的时间状语。
“health problems”表示健康问题。
短语及拓展:
拓展短语:“medical problems”表示“医疗问题”。
Factories have also polluted the land and the water .
主语:Factories
谓语:have also polluted
宾语:the land and the water
知识点:
“also”表示“也”。
“pollute”表示“污染”。
短语及拓展:
拓展短语:“pollute the environment”表示“污染环境”。
As a result , many rivers and lakes are now dead .
结果状语从句:As a result
主句:many rivers and lakes are now dead
知识点:
“As a result”表示结果。
“dead”用于形容河流、湖泊等失去生命力。
短语及拓展:
拓展短语:“in the end”也表示“最后,结果”。
Around the earth, there's a special kind of oxygen called "ozone" (O ).
主语:a special kind of oxygen
谓语:is
表语:there(存在句中的形式主语),a special kind of oxygen
定语:Around the earth(介词短语作地点状语),called "ozone" (O )(过去分词短语作后置定语)
知识点:
存在句结构:There + be + 主语
介词短语作状语:Around the earth
过去分词短语作定语:called "ozone" (O )
短语拓展:
a kind of:一种
be called:被称为
It is important to the earth.
主语:It
谓语:is
表语:important
状语:to the earth(介词短语作状语)
知识点:
形式主语It的用法
介词短语作状语
短语拓展:
be important to sb./sth.:对某人/某物是重要的
But now air pollution is destroying it and making a very big hole in the ozone layer.
主语:air pollution
谓语:is destroying,is making(并列谓语)
宾语:it,a very big hole
状语:now(时间状语),in the ozone layer(介词短语作地点状语)
知识点:
并列谓语
介词短语作状语
短语拓展:
make a hole in:在...上打个洞
ozone layer:臭氧层
Too much harmful radiation from the sun passes through the hole and reaches the earth directly.
主语:Too much harmful radiation
谓语:passes through,reaches(并列谓语)
宾语:the hole,the earth
状语:from the sun(介词短语作定语),directly(副词作状语)
知识点:
并列谓语
介词短语作定语
副词作状语
短语拓展:
pass through:穿过
reach sth. directly:直接到达某物
This is very dangerous because this kind of radiation can cause cancer.
主句:This is very dangerous
主语:This
谓语:is
表语:very dangerous
从句:because this kind of radiation can cause cancer(原因状语从句)
主语:this kind of radiation
谓语:can cause
宾语:cancer
知识点:
原因状语从句
情态动词can的用法
短语拓展:
be dangerous:危险的
cause cancer:致癌
Carbon dioxide (CO2) in the air has increased a lot.
主语:Carbon dioxide (CO2) in the air
谓语:has increased
状语:a lot(副词短语作状语)
知识点:
现在完成时
介词短语作定语
短语拓展:
increase a lot:增加很多
It mainly comes from burning oil, coal and wood.
主语:It
谓语:comes
状语:mainly(副词作状语)
宾语:from burning oil, coal and wood(介词短语作状语)
知识点:
介词短语作状语
短语拓展:
come from:来自
burn sth.:燃烧某物
This has formed a blanket around the earth.
主语:This
谓语:has formed
宾语:a blanket
状语:around the earth(介词短语作状语)
知识点:
现在完成时
介词短语作状语
短语拓展:
form a blanket:形成一层毯子
The heat from the sun can't escape so the temperature is rising.
主句:The heat from the sun can't escape
主语:The heat
谓语:can't escape
结果状语从句:so the temperature is rising
主语:the temperature
谓语:is rising
知识点:
结果状语从句
情态动词can't的用法
短语拓展:
escape from:从...逃脱
rise in temperature:气温上升
This is called "the greenhouse effect".
主语:This
谓语:is called
宾语:"the greenhouse effect"
知识点:
被动语态
短语拓展:
greenhouse effect:温室效应
It causes the level of the oceans to rise and the climate of the earth to change.
主语:It
谓语:causes
宾语:the level of the oceans to rise,the climate of the earth to change(并列宾语,使用不定式作宾语补足语)
知识点:
并列宾语
不定式作宾语补足语
短语拓展:
cause sth. to do sth.:导致某物做某事
rise in level:水平上升
change in climate:气候变化
All these problems are very serious , so we must do something now .
主语:All these problems
谓语:are
表语:very serious
并列连词:so
第二个句子:
主语:we
谓语:must do
宾语:something
时间状语:now
知识点:
限定词“All”用于指代整体,强调所有这些问题。
系动词“are”与形容词“serious”搭配,形成系表结构,描述问题的性质。
并列连词“so”连接两个句子,表示因果关系;情态动词“must”表示必要性;时间状语“now”强调当前行动的重要性。
不定代词“something”用于肯定句,表示某事或某物。
时间副词“now”用于指示当前的时间或状态。
短语拓展:
All kinds of, All in all, All the time
be very important, be very helpful, be very difficult
so that, so far, must have done, now and then
do something about, do something for, do nothing
at this moment, from now on, just now