Section Ⅰ TOPIC TALK & LESSON 1
Period 1 单元词汇表
1．_________vt．破坏；毁掉 2．_________vi．& vt．转换，改变 3．_________vi．& vt．猎取，猎杀 4．_________adj．大量的 5．_________adj．各种各样的，形形色色的 6．_________n．减少；减少的量vi．& vt．减少 7．_________vt．责怪，指责 8．_________vt．影响 9．_________vt．(使)恢复 10．plastic adj．________ 11．mining n．________ 12．item n．________ 13．species n．________ 14．wipe vt．_________ 15．solar adj．_________ 16．hatch vi．& vt．_________ 1．No one was injured in the explosion，but the building_________ (destroy) completely． 2．Do you remember_________ (switch) the lights off before we came out 3．_________(hunt) was one of Italy's most popular sports，according to the survey carried out last year． 4．It is reported that fatal road accidents_________ (decrease) in frequency over recent years． 5．An ice storm in the Northeast is_________ (blame) for many of those problems． 6．A child's behaviour can_________ (affect) by his unhappy home environment． 7．The measures are intended_________ (restore) public confidence in the economy． 8．The hen must find a warm place_________ (hatch) her eggs．
1．conserve v．保存；保护；保藏→_________n．保护→_________adj．保守的；守旧的 2．recycle vi．& vt．再利用，回收利用→_________adj．可回收利用的→_________adj．不可回收的 3．threat n．威胁；(灾难等坏事)发生的可能→_________v．威胁；恐吓；危及→_________adj．威胁的 4．inform vt．通知；告知→_________n．信息→_________adj．有教育意义的；知识性强的 5．legal adj．合法的→_________adv．合法地→_________adv．非法地，违法地 6．extinct adj．灭绝的，绝种的→_________n．灭绝；绝种；消亡 7．incredible adj．极好的；难以置信的→_________adv．非常地，极端地 8．urge v．催促；敦促；力劝；强烈要求→_________adj．紧急的，急迫的→_________n．紧迫；急迫；紧急的事 9．usual adj．经常的，通常的；寻常的，惯常的→_________adj．异常的；不平常的 10．vary v．变化；不同→_________adj．各种各样的，形形色色的→_________n．变化；品种；种类；多样化 11．endanger vt．危及，使遭受危险→_________adj．濒危的 1．He was interested in wildlife_________ and he proposed the local government should introduce some tough new laws_____________ wildlife in the area．(conserve) 2．_________materials must be_________ in order to protect our environment．(recycle) 3．The situation could worsen if storms move north and_________ (threat) winter grain supplies． 4．We do not have any more_________ (inform) at the present time． 5．Suppose you satisfy your desire_________ (legally)，don't you think that you will be punished for that？ 6．An operation is beginning to try to save a species of crocodile from_________ (extinct)． 7．He lives a very simple life for a person who has become_________ (incredible) rich． 8．I am afraid you have not realised the_________ (urgent) of the matter． 9．He leads a full and_________ life and he often goes to the club nearby，which provides a wide_________ of activities including tennis，swimming and basketball．(vary) 10．It won't have escaped your notice that I've been_________ (unusual) busy in the past week． 11．Look out! There are some dangerous animals in the area，including North Atlantic right whale，which is an_________ (endanger) species．
1．_____________起某种作用 2．_____________尽自己的职责 3．_____________彻底毁灭 4．_____________(对某事)负有责任 5．_____________消失；绝迹，灭绝 6．_____________处境危险，受到威胁 7．_____________采取行动 8．_____________简而言之 1．If we don't solve the problem of global warming，our next generation will_____________． 2．Every one of us_____________ in protecting the environment． 3．The disease threatens to_____________ the entire population． 4．Alone in his room，he asked himself whether he_____________ for the accident． 5．There are new uses of words coming in and old uses_____________．
由新知联想已知
1．conservation n．保护 [联想] ①protection n．保护 ②defence n．保护；防卫 2．die out 消失；绝迹，灭绝 [联想] ①disappear v．消失；不见；灭绝 ②die from 死于；因……而死 ③die of 因……死；死于 3．decrease n．减少；减少的量vi．& vt．减少 [联想] ①reduce vt．减少 ②fall vi．减少 ③cut down减少 4．endangered adj．濒危的 [联想] ①dangerous adj．危险的 ②in danger 处于危险之中
第一篇课文
①entire species整个物种
②wipe out彻底毁灭
③unusual adj．异常的；不平常的
④in fact事实上
⑤the third mass extinction第三次生物大灭绝
⑥known as以……而著称
⑦varied adj．各种各样的，形形色色的
⑧according to根据
⑨volcanic eruptions火山喷发
⑩asteroid n．小行星
the decrease of the oxygen content含氧量下降
global warming全球变暖
human activity人类活动
be to blame (对某事)负有责任
die out 消失；绝迹，灭绝
cause for concern令人担心的原因
due to natural causes由于自然原因
that is即
a long list of reasons很多原因
factory farming工业化种植
overfishing n．过度捕捞
negatively affect all other species对所有其他物种都有负面影响
study the issue研究这个问题
up to three quarters of多达四分之三的……
depend on依靠
be at risk of处于……的危险或威胁中
the balance in nature自然平衡
have no air to breathe没有可以呼吸的空气
be unable to survive无法生存
take action采取行动
take steps to do．．．采取措施做……
save endangered species拯救濒危物种
set up special areas建立特别保护区
natural sources of energy天然能源
solar energy太阳能
in short简而言之
stop destroying the planet停止破坏星球
only five black robins left只剩下5只黑知更鸟
off the coast of New Zealand离新西兰海岸不远
lay eggs下蛋
wildlife workers野生动物工作者
begin a programme for开始……的计划
hatch vi．& vt．(使)孵化
take care of the chicks照顾雏鸟
thanks to their efforts由于他们的努力
restore their habitats恢复它们的栖息地
THE SIXTH EXTINCTION
Extinctions，where entire species① are wiped out②(1)，are not unusual③ in our Earth's history．In fact④，over 90 percent of all species that ever lived(2) are now extinct．In the last 500 million years，there have been five times when life on Earth has almost ended(3)．These include the third mass extinction⑤，known as⑥ the “Great Dying”，which killed 90% to 96% of all species(4)．And the fifth event，which occurred 66 million years ago(5)，caused the death of the dinosaurs．The reasons for extinctions are varied⑦．According to⑧ scientists，they include volcanic eruptions⑨，asteroids⑩ hitting the Earth from space，changes in sea levels，the decrease of the oxygen content of the sea and global warming ．Many scientists say we are now entering the Earth's sixth mass extinction(6)．This time，human activity will be to blame ．
(1)where引导非限制性定语从句，修饰先行词Extinctions。
(2)that引导限制性定语从句，修饰先行词species。
(3)when引导限制性定语从句，修饰先行词five times。
(4)which引导非限制性定语从句，修饰先行词the third mass extinction。
(5)which引导非限制性定语从句，修饰先行词the fifth event。
(6)该句为省略that的宾语从句。
Although it is not unusual for species to die out naturally，the rate at which this is now happening is cause for concern ．(7) A 2015 study by scientists who were based at Brown University and Duke University in the US，looked at how quickly species die out due to natural causes ，that is ，the “background extinction rate”．(8) They found that human activity is causing species to die out 1，000 times faster than normal(9)．There is a long list of reasons why so many species are dying out(10)：air and water pollution，forests being destroyed，factory farming and overfishing ．It is clear that human activity has negatively affected all other species on Earth，including animals and plants．(11)
(7)句中Although引导让步状语从句；at which．．．happening为限制性定语从句，修饰先行词the rate。
(8)句中who．．．the US为限制性定语从句，修饰先行词scientists；how．．．natural causes为宾语从句。
(9)that引导宾语从句。
(10)why引导限制性定语从句，修饰先行词reasons。
(11)It为形式主语，真正的主语为后面的that从句。
If a sixth mass extinction occurs，scientists who have studied the issue believe that up to three quarters of all species on Earth could die out．(12) Of course，as we humans depend on so many species for our survival(13)，we would also be at risk of dying out．Our world and our lives depend on the balance in nature between animals and plants．Without forests，we would have no air to breathe ，and without clean water we would be unable to survive ．
(12)句中If引导条件状语从句；who．．．the issue为限制性定语从句，修饰先行词scientists；that．．．die out为宾语从句。
(13)as引导原因状语从句。
Can a sixth extinction be avoided？Experts say that it is not yet too late，if we take action now．(14)This would mean we have to significantly change the way we live(15)．For example，we need to take steps to save endangered species ，including setting up special areas where plants and animals can be protected(16)．We need to change how we work and travel by using cleaner，more natural sources of energy ，such as wind and solar energy (17)．We also need to improve our farming methods to reduce water，air and land pollution．In short ，if we want to survive，we need to stop destroying the planet that we live on and start to protect it．(18)
(14)句中that引导宾语从句；if we take action now为条件状语从句。
(15)该句为省略that的宾语从句，其中we live为限制性定语从句，修饰先行词the way。
(16)where引导限制性定语从句，修饰先行词special areas。
(17)how引导宾语从句。
(18)句中if引导条件状语从句；that we live on为限制性定语从句，修饰先行词the planet。
The Black Robin
Black robins are the birds that humans saved from extinction(19)．In 1980，there were only five black robins left in the world．They all lived on a small island off the coast of New Zealand ．Only one of those birds，a female called Old Blue，was able to lay eggs ．Wildlife workers began a programme for raising black robin chicks．They protected Old Blue's eggs，helped them to hatch ，and took care of the chicks ．Thanks to their efforts ，there are now more than 250 black robins，and the population is spreading．To help them survive，people are restoring their habitats and removing small animals that hunt them，such as mice and cats from the islands where they live．(20)
(19)that引导限制性定语从句，修饰先行词the birds。
(20)句中that hunt them为限制性定语从句，修饰先行词small animals；where they live也是限制性定语从句，修饰先行词the islands。
第六次生物大灭绝
物种灭绝，即某个物种的完全消失，在地球的历史上并不罕见。事实上，曾经存在过的物种超过90%现在都已经灭绝。在过去的5亿年里，地球上的生命有5次几乎灭绝。其中包括第三次生物大灭绝，即所谓的“大灭绝”，导致90%到96%的物种灭绝。发生在6 600万年前的第五次灭绝事件导致了恐龙的灭亡。灭绝的原因多种多样。科学家们认为，造成物种灭绝的原因包括火山喷发、小行星从太空撞击地球、海平面高度改变、海水中含氧量下降和全球变暖等。许多科学家说，我们现在正在进入地球的第六次大灭绝。这一次，人类活动将是罪魁祸首。
虽然物种的自然灭绝并不罕见，但现在灭绝的速度让人担忧。美国布朗大学和杜克大学的科学家们于2015年进行了一项研究，考察了自然原因导致物种灭绝的速度，即“背景灭绝率”。他们发现，人类活动导致物种灭绝的速度是正常情况下的1 000倍。造成如此多的物种灭绝的原因有很多：空气和水污染、森林被破坏、工业化种植和过度捕捞。很明显，人类活动已经对地球上所有其他物种产生了负面影响，包括动物和植物。
研究这个问题的科学家们认为，如果第六次大灭绝发生，地球上多达四分之三的物种可能就会灭绝。当然，由于我们人类依靠如此多的物种生存，我们也将面临灭绝的风险。我们的世界和我们的生活依赖于动物和植物之间的自然平衡。没有森林，我们就没有可以呼吸的空气，没有干净的水，我们就无法生存。
第六次物种灭绝可以避免吗？专家们说，如果我们现在就采取行动，还为时不晚。这意味着我们必须显著地改变我们的生活方式。例如，我们需要采取措施拯救濒危物种，包括建立特别保护区，在这里动植物可以得到保护。我们需要通过使用更清洁、更天然的能源来改变工作和旅行的方式，如风能和太阳能。我们还需要改进我们的耕作方法，以减少对水、空气和土地的污染。简而言之，如果我们想要生存，我们需要停止破坏我们赖以生存的星球，并开始保护它。
黑知更鸟
黑知更鸟是人类从灭绝中拯救出来的鸟类。1980年，世界上只剩下5只黑知更鸟。它们都生活在离新西兰海岸不远的一个小岛上。其中只有一只名叫老布鲁的雌鸟能下蛋。野生动物工作者开始了饲养黑知更鸟雏鸟的计划。他们保护老布鲁的蛋，帮助它们孵化并照顾雏鸟。由于他们的努力，现在有了250多只黑知更鸟，而且数量还在增加。为了帮助它们生存，人们正在恢复它们的栖息地，并将捕食它们的小动物，如老鼠和猫，从它们生活的岛屿上赶走。
Period 1
速记·重点词汇——牢记词形和词义
1．destroy 2．switch 3．hunt 4．mass 5．varied 6．decrease 7．blame 8．affect 9．restore 10．塑料制的 11．采矿业 12．一项，一条 13．物种，种 14．擦；拭 15．太阳光(能)的 16．(使)孵化
运用·语境填空——测试一下基本功
1．was destroyed 2．switching 3．Hunting 4．have decreased
5．to blame 6．be affected 7．to restore 8．to hatch
速记·派生词汇——牢记词形和词义
1．conservation；conservative 2．recyclable；unrecyclable 3．threaten；threatening 4．information；informative
5．legally；illegally 6．extinction 7．incredibly 8．urgent；urgency 9．unusual 10．varied；variety 11．endangered
运用·语境填空——测试一下基本功
1．conservation；to conserve 2．Recyclable；recycled 3．threaten 4．information 5．illegally 6．extinction 7．incredibly 8．urgency 9．varied；variety 10．unusually 11．endangered
速记·重点短语——记牢搭配和意义
1．have a role 2．do one's part 3．wipe out 4．be to blame 5．die out 6．be at risk 7．take action 8．in short
运用·语境填空——测试一下基本功
1．be at risk 2．has a role 3．wipe out 4．was to blame 5．dying out
1 / 9(共39张PPT)
复习任务群一
现代文阅读Ⅰ
把握共性之“新” 打通应考之“脉”
UNIT 3 CONSERVATION
主题语境 人与自然——人类生存、社会发展与环境的关系
Period 1 课时练案 单元词汇表
Section Ⅰ TOPIC TALK & LESSON 1
1．_______ vt．破坏；毁掉
2．______ vi．& vt．转换，改变
3．____ vi．& vt．猎取，猎杀
4．____ adj．大量的
5．______ adj．各种各样的，形形色色的
6．________ n．减少；减少的量vi．& vt．减少
7．_____ vt．责怪，指责
8．______ vt．影响
destroy
switch
hunt
mass
varied
decrease
blame
affect
9．______ vt．(使)恢复
10．plastic adj．________
11．mining n．______
12．item n．__________
13．species n．________
14．wipe vt．______
15．solar adj．______________
16．hatch vi．& vt．__________
restore
塑料制的
采矿业
一项，一条
物种，种
擦；拭
太阳光(能)的
(使)孵化
1．No one was injured in the explosion，but the building ______________ (destroy) completely．
2．Do you remember _________ (switch) the lights off before we came out
3．_______ (hunt) was one of Italy's most popular sports，according to the survey carried out last year．
4．It is reported that fatal road accidents _____________ (decrease) in frequency over recent years．
was destroyed
switching
Hunting
have decreased
5．An ice storm in the Northeast is _________ (blame) for many of those problems．
6．A child's behaviour can ____________ (affect) by his unhappy home environment．
7．The measures are intended ___________ (restore) public confidence in the economy．
8．The hen must find a warm place _________ (hatch) her eggs．
to blame
be affected
to restore
to hatch
1．conserve v．保存；保护；保藏→____________ n．保护→____________ adj．保守的；守旧的
2．recycle vi．& vt．再利用，回收利用→__________ adj．可回收利用的→____________ adj．不可回收的
3．threat n．威胁；(灾难等坏事)发生的可能→________ v．威胁；恐吓；危及→___________ adj．威胁的
conservation
conservative
recyclable
unrecyclable
threaten
threatening
1．He was interested in wildlife ____________ and he proposed the local government should introduce some tough new laws ____________ wildlife in the area．(conserve)
2．__________ materials must be ________ in order to protect our environment．(recycle)
3．The situation could worsen if storms move north and ________ (threat) winter grain supplies．
conservation
to conserve
Recyclable
recycled
threaten
4．inform vt．通知；告知→___________ n．信息→___________ adj．有教育意义的；知识性强的
5．legal adj．合法的→_______ adv．合法地→_________ adv．非法地，违法地
6．extinct adj．灭绝的，绝种的→__________ n．灭绝；绝种；消亡
7．incredible adj．极好的；难以置信的→__________ adv．非常地，极端地
information
informative
legally
illegally
extinction
incredibly
8．urge v．催促；敦促；力劝；强烈要求→______ adj．紧急的，急迫的→_______ n．紧迫；急迫；紧急的事
9．usual adj．经常的，通常的；寻常的，惯常的→_______ adj．异常的；不平常的
10．vary v．变化；不同→______ adj．各种各样的，形形色色的→_______ n．变化；品种；种类；多样化
11．endanger vt．危及，使遭受危险→__________ adj．濒危的
urgent
urgency
unusual
varied
variety
endangered
4．We do not have any more ___________ (inform) at the present time．
5．Suppose you satisfy your desire _________ (legally)，don't you think that you will be punished for that？
6．An operation is beginning to try to save a species of crocodile from __________ (extinct)．
information
illegally
extinction
7．He lives a very simple life for a person who has become __________ (incredible) rich．
8．I am afraid you have not realised the _______ (urgent) of the matter．
9．He leads a full and ______ life and he often goes to the club nearby，which provides a wide _______ of activities including tennis，swimming and basketball．(vary)
incredibly
urgency
varied
variety
10．It won't have escaped your notice that I've been _________ (unusual) busy in the past week．
11．Look out! There are some dangerous animals in the area，including North Atlantic right whale，which is an _________ (endanger) species．
unusually
endangered
1．_____________ 起某种作用
2．________________ 尽自己的职责
3．_________ 彻底毁灭
4．_____________ (对某事)负有责任
5．________ 消失；绝迹，灭绝
6．____________ 处境危险，受到威胁
7．____________ 采取行动
8．_________ 简而言之
have a role
do one's part
wipe out
be to blame
die out
be at risk
take action
in short
1．If we don't solve the problem of global warming，our next generation will ____________．
2．Every one of us ____________ in protecting the environment．
3．The disease threatens to _________ the entire population．
4．Alone in his room，he asked himself whether he ____________ for the accident．
5．There are new uses of words coming in and old uses __________．
be at risk
has a role
wipe out
was to blame
dying out
1．conservation n．保护
[联想] ①protection n．保护
②defence n．保护；防卫
2．die out 消失；绝迹，灭绝
[联想] ①disappear v．消失；不见；灭绝
②die from 死于；因……而死
③die of 因……死；死于
由新知联想已知
3．decrease n．减少；减少的量vi．& vt．减少
[联想] ①reduce vt．减少
②fall vi．减少
③cut down减少
4．endangered adj．濒危的
[联想] ①dangerous adj．危险的
②in danger 处于危险之中
第一篇课文
①entire species整个物种
②wipe out彻底毁灭
③unusual adj．异常的；不平常的
④in fact事实上
⑤the third mass extinction第三次生物大灭绝
⑥known as以……而著称
⑦varied adj．各种各样的，形形色色的
⑧according to根据
⑨volcanic eruptions火山喷发
⑩asteroid n．小行星
the decrease of the oxygen content含氧量下降
global warming全球变暖
human activity人类活动
be to blame (对某事)负有责任
die out 消失；绝迹，灭绝
cause for concern令人担心的原因
due to natural causes由于自然原因
that is即
a long list of reasons很多原因
factory farming工业化种植
overfishing n．过度捕捞
negatively affect all other species对所有其他物种都有负面影响
study the issue研究这个问题
up to three quarters of多达四分之三的……
depend on依靠
be at risk of处于……的危险或威胁中
the balance in nature自然平衡
have no air to breathe没有可以呼吸的空气
be unable to survive无法生存
take action采取行动
take steps to do…采取措施做……
save endangered species拯救濒危物种
set up special areas建立特别保护区
natural sources of energy天然能源
solar energy太阳能
in short简而言之
stop destroying the planet停止破坏星球
only five black robins left只剩下5只黑知更鸟
off the coast of New Zealand离新西兰海岸不远
lay eggs下蛋
wildlife workers野生动物工作者
begin a programme for开始……的计划
hatch vi．& vt．(使)孵化
take care of the chicks照顾雏鸟
thanks to their efforts由于他们的努力
restore their habitats恢复它们的栖息地
THE SIXTH EXTINCTION
Extinctions，where entire species① are wiped out②(1)，are not unusual③ in our Earth's history．In fact④，over 90 percent of all species that ever lived(2) are now extinct．In the last 500 million years，there have been five times when life on Earth has almost ended(3)．These include the third mass extinction⑤，known as⑥ the “Great Dying”，which killed 90% to 96% of all species(4)．And the fifth event，which occurred 66 million years ago(5)，caused the death
of the dinosaurs．The reasons for extinctions are varied⑦．According to⑧ scientists，they include volcanic eruptions⑨，asteroids⑩ hitting the Earth from space，changes in sea levels，the decrease of the oxygen content of the sea and global warming ．Many scientists say we are now entering the Earth's sixth mass extinction(6)．This time，human activity will be to blame ．
(1)where引导非限制性定语从句，修饰先行词Extinctions。
(2)that引导限制性定语从句，修饰先行词species。
(3)when引导限制性定语从句，修饰先行词five times。
(4)which引导非限制性定语从句，修饰先行词the third mass extinction。
(5)which引导非限制性定语从句，修饰先行词the fifth event。
(6)该句为省略that的宾语从句。
Although it is not unusual for species to die out naturally，the rate at which this is now happening is cause for concern ．(7) A 2015 study by scientists who were based at Brown University and Duke University in the US，looked at how quickly species die out due to natural causes ，that is ，the “background extinction rate”．(8) They found that human activity is causing species to die out 1，000 times faster than normal(9)．There is a long list of reasons why so many species are dying out(10)：air and water pollution，forests being destroyed，factory farming and overfishing ．It is clear that human activity has negatively affected all other species on Earth，including animals and plants．(11)
(7)句中Although引导让步状语从句；at which… happening为限制性定语从句，修饰先行词the rate。
(8)句中who… the US为限制性定语从句，修饰先行词scientists；how… natural causes为宾语从句。
(9)that引导宾语从句。
(10)why引导限制性定语从句，修饰先行词reasons。
(11)It为形式主语，真正的主语为后面的that从句。
If a sixth mass extinction occurs，scientists who have studied the issue believe that up to three quarters of all species on Earth could die out．(12) Of course，as we humans depend on so many species for our survival(13)，we would also be at risk of dying out．Our world and our lives depend on the balance in nature between animals and plants．Without forests，we would have no air to breathe ，and without clean water we would be unable to survive ．
(12) 句中If引导条件状语从句；who…the issue为限制性定语从句，修饰先行词scientists；that…die out为宾语从句。
(13)as引导原因状语从句。
Can a sixth extinction be avoided？Experts say that it is not yet too late，if we take action now．(14)This would mean we have to significantly change the way we live(15)．For example，we need to take steps to save endangered species ，including setting up special areas where plants and animals can be protected(16)．We need to change how we work and travel by using cleaner，more natural sources of energy ，such as wind and solar energy (17)．We also need to improve our farming methods to reduce water，air and land pollution．In short ，if we want to survive，we need to stop destroying the planet that we live on and start to protect it．(18)
(14)句中that引导宾语从句；if we take action now为条件状语从句。
(15)该句为省略that的宾语从句，其中we live为限制性定语从句，修饰先行词the way。
(16)where引导限制性定语从句，修饰先行词special areas。
(17)how引导宾语从句。
(18)句中if引导条件状语从句；that we live on为限制性定语从句，修饰先行词the planet。
The Black Robin
Black robins are the birds that humans saved from extinction(19)．In 1980，there were only five black robins left in the world．They all lived on a small island off the coast of New Zealand ．Only one of those birds，a female called Old Blue，was able to lay eggs ．Wildlife workers began a programme for raising black robin chicks．They protected Old Blue's eggs，helped them to hatch ，and took care of the chicks ．Thanks to their efforts ，there are now more than 250 black robins，and the population is spreading．To help them survive，people are restoring their habitats and removing small animals that hunt them，such as mice and cats from the islands where they live．(20)
(19)that引导限制性定语从句，修饰先行词the birds。
(20)句中that hunt them为限制性定语从句，修饰先行词small animals；where they live也是限制性定语从句，修饰先行词the islands。
第六次生物大灭绝
物种灭绝，即某个物种的完全消失，在地球的历史上并不罕见。事实上，曾经存在过的物种超过90%现在都已经灭绝。在过去的5亿年里，地球上的生命有5次几乎灭绝。其中包括第三次生物大灭绝，即所谓的“大灭绝”，导致90%到96%的物种灭绝。发生在6 600万年前的第五次灭绝事件导致了恐龙的灭亡。灭绝的原因多种多样。科学家们认为，造成物种灭绝的原因包括火山喷发、小行星从太空撞击地球、海平面高度改变、海水中含氧量下降和全球变暖等。许多科学家说，我们现在正在进入地球的第六次大灭绝。这一次，人类活动将是罪魁祸首。
虽然物种的自然灭绝并不罕见，但现在灭绝的速度让人担忧。美国布朗大学和杜克大学的科学家们于2015年进行了一项研究，考察了自然原因导致物种灭绝的速度，即“背景灭绝率”。他们发现，人类活动导致物种灭绝的速度是正常情况下的1 000倍。造成如此多的物种灭绝的原因有很多：空气和水污染、森林被破坏、工业化种植和过度捕捞。很明显，人类活动已经对地球上所有其他物种产生了负面影响，包括动物和植物。
研究这个问题的科学家们认为，如果第六次大灭绝发生，地球上多达四分之三的物种可能就会灭绝。当然，由于我们人类依靠如此多的物种生存，我们也将面临灭绝的风险。我们的世界和我们的生活依赖于动物和植物之间的自然平衡。没有森林，我们就没有可以呼吸的空气，没有干净的水，我们就无法生存。
第六次物种灭绝可以避免吗？专家们说，如果我们现在就采取行动，还为时不晚。这意味着我们必须显著地改变我们的生活方式。例如，我们需要采取措施拯救濒危物种，包括建立特别保护区，在这里动植物可以得到保护。我们需要通过使用更清洁、更天然的能源来改变工作和旅行的方式，如风能和太阳能。我们还需要改进我们的耕作方法，以减少对水、空气和土地的污染。简而言之，如果我们想要生存，我们需要停止破坏我们赖以生存的星球，并开始保护它。
黑知更鸟
黑知更鸟是人类从灭绝中拯救出来的鸟类。1980年，世界上只剩下5只黑知更鸟。它们都生活在离新西兰海岸不远的一个小岛上。其中只有一只名叫老布鲁的雌鸟能下蛋。野生动物工作者开始了饲养黑知更鸟雏鸟的计划。他们保护老布鲁的蛋，帮助它们孵化并照顾雏鸟。由于他们的努力，现在有了250多只黑知更鸟，而且数量还在增加。为了帮助它们生存，人们正在恢复它们的栖息地，并将捕食它们的小动物，如老鼠和猫，从它们生活的岛屿上赶走。
谢 谢！
