A
Passenger pigeons(旅鸽) were the most common birds in all of North America in the 1800s.It was common to see large groups of passenger pigeons—groups that made a sound like a storm.But today,they are extinct because of human behavior.Now,some scientists want to bring passenger pigeons back to life by using new technology and scientific ideas.They call this process de-extinction.
De-extinction has not happened yet.It is still just an idea.The process of de-extinction is not easy.First,scientists must collect DNA from the bodies of extinct animals.Then they will put it in the eggs of similar animal species.When these animals become adults,they will have babies.And these baby animals will have the DNA of the extinct animals.
Scientists believe it is possible to bring back passenger pigeons and many other animals.However,not everyone thinks this is a good idea.
Stuart Primm is the world’s leading expert on modern animal extinction.He believes that bringing extinct animals back to life is bad for the earth.On the one hand,these animals no longer have a safe place to live.On the other hand,they could cause other animals to die.
Many other scientists do not agree with Stuart Primm.Stuart Brand,a writer and scientist,is one of them.He believes de-extinction is good for many reasons.
“The current generation (当代) of children will experience the return of some unusual animals in their lifetime.It may be part of what defines their generation and their attitude to the natural world.They will take their parents to zoos to see the growing populations of passenger pigeons,and maybe even dodo birds.This will provide a good deal of money for zoos busy with extinct species restoration (恢复).Humans killed off a lot of species over the last 10,000 years.So,it’s right to bring some back to life,” he said.
21.In the 19th century,passenger pigeons .
A.were common sightings
B.suffered a lot from storms
C.lived mainly in North America
D.were the largest in American history
答案A
解析细节理解题。根据第一段中的“PassengerpigeonswerethemostcommonbirdsinallofNorthAmericainthe1800s.Itwascommontoseelargegroupsofpassengerpigeons—groupsthatmadeasoundlikeastorm.”可知,19世纪时的旅鸽数目众多。
22.What do we know about de-extinction?
A.It will change the DNA of the extinct animals.
B.It was first used in passenger pigeons.
C.It is difficult to carry out.
D.It proved to be useful.
答案C
解析细节理解题。根据第二段中的“Theprocessofde-extinctionisnoteasy.”以及接下来具体介绍灭绝物种复活的复杂过程可知,复活灭绝物种绝非易事。
23.Why is Stuart Primm against bringing back extinct animals?
A.They will die very soon.
B.They will create other problems.
C.They will do great harm to humans.
D.They will replace the similar species.
答案B
解析推理判断题。根据第四段中的“Hebelievesthatbringingextinctanimalsbacktolifeisbadfortheearth...theseanimalsnolongerhaveasafeplacetolive.”和“theycouldcauseotheranimalstodie”可知,StuartPrimm反对复活灭绝物种是因为他认为这些复活的动物会造成一些新的问题。
24.How does Stuart Brand feel about de-extinction?
A.Wrong. B.Difficult.
C.Important. D.Wasteful.
答案C
解析观点态度题。根据倒数第二段中的“Hebelievesde-extinctionisgoodformanyreasons”以及StuartBrand在最后一段具体陈述复活灭绝物种的好处可知,他认为复活灭绝物种很重要。
