2020-2021学年人教版英语选修8习题：课时作业5 UNIT 2 WARMING UP .doc

1、阅读理解AConservationists in Brazil are ready to try cloning eight animals that are under pressure, including jaguars and manned wolves.Other conservation groups have welcomed the plan, but say the priority (优先)should always be to preserve species in the wild by reducing hunting and maintaining habitats

2、(栖息地)“While cloning is a tool of last resort (手段), it may prove valuable for some species，” says Ian Harrison，a conservationist in Virginia.“Experimenting with it now, using species that are not at immediate risk of extinction，is important.”None of these animals are endangered, but Brazils agricultu

3、ral research agency, Embrapa, wants a headstart.The eight species live in the Cerrado, a tropical plain.They will be cloned and kept as a reserve in case wild populations collapse (崩溃). As well as jaguars and manned wolves, the researchers also hope to clone black lion tamarins，bush dogs，coatis，coll

4、ared anteaters, gray brocket deer and bison.Embrapa created Brazils first cloned animal in 2001, a cow that died last year.It has cloned over 100 animals, mainly cows and horses.Rare animals have been cloned before, including the oxlike gaur (野牛)and a wild cow.Since then, more cloning techniques hav

5、e been developed, increasing the chances of success.“The key is to save a little piece of skin, blood or other living cells before the genes from these individuals are lost from the planet forever.A freezer could store the genetics for all the pandas in China, or all the mountain gorillas in Africa，

6、” says Robert Lanza, who headed the group that produced the gaur.“If you have the genetic material you can clone and reintroduce genetic diversity whenever you want.”Rhiannon Lloyd of the University of Portsmouth, UK, runs a facility that stores DNA of threatened and extinct species.She backs Embrap

7、as plan：“Collecting from dead specimens (标本) prevents the valuable information within their cells being lost forever.”本文报道了巴西将克隆八种濒危动物这一则消息。1What is Ian Harrisons attitude towards Embrapas cloning of eight species?ACritical.BNegative. CSubjective.DSupporting.答案：D解析：观点态度题。从第二段最后一句“Experimenting with

8、it now, using species that.is important.”可知，Ian Harrison对克隆八种动物的计划持赞同的态度，故选D。2Why does Embrapa plan to clone the eight species?ATo test their chances of survival.BTo warn hunters to stop hunting.CTo prevent them from collapsing.DTo remind people of their habitats.答案：C解析：细节理解题。从第三段第三句“They will be cl

9、oned and kept as a reserve in case wild populations collapse(崩溃)”可知，克隆的目的是防止这些物种灭绝，故选C。3The eight species include the following except _.Agray brocket deerBmanned wolves Coxlike gaurs Dbush dogs答案：C解析：细节理解题。从第三段的“As well as jaguars and manned wolves，the researchers also hope to clone black lion tama

10、rins，bush dogs，coatis，collared anteaters，gray brocket deer and bison.”可知，oxlike gaur不在这八大物种之列，故选C。4It is implied in the text that _.Aso far no rare animals have been cloned in the worldBEmbrapa has cloned many endangered animals since 2001Ccloning cant lead to genetic diversity among the eight speci

11、esDit will be more successful to clone these endangered species in the future答案：D解析：推理判断题。从第四段最后一句“Since then，more cloning techniques have been developed，increasing the chances of success.”和第五、六段的内容可知，克隆技术越来越高，克隆出的动物存活率也越来越高，故选D。BNo one is sure how the ancient Egyptians built the pyramids near Cairo

12、.But a new study suggests they used a little rock n roll.Longago builders could have attached wooden poles to the stones and rolled them across the sand，the scientists say.“Technically, I think what theyre proposing is possible，” physicist Daniel Bonn said.People have long puzzled over how the Egypt

13、ians moved such huge rocks. And theres no obvious answer.On average, each of the two million big stones weighed about as much as a large pickup truck. The Egyptians somehow moved the stone blocks to the pyramid site from about one kilometer away.The most popular view is that Egyptian workers slid th

14、e blocks along smooth paths. Many scientists suspect workers first would have put the blocks on sleds (滑板)Then they would have dragged them along paths.To make the work easier, workers may have lubricated_the_paths either with wet clay or with the fat from cattle.Bonn has now tested this idea by bui

15、lding small sleds and dragging heavy objects over sand.Evidence from the sand supports this idea. Researchers found small amounts of fat, as well as a large amount of stone and the remains of paths.However, physicist Joseph West thinks there might have been a simpler way, who led the new study. West

16、 said, “I was inspired while watching a television program showing how sleds might have helped with pyramid construction. I thought, Why dont they just try rolling the things？”A square could be turned into a rough sort of wheel by attaching wooden poles to its sides, he realized.That, he notes, shou

17、ld make a block of stone “a lot easier to roll than a square”So he tried it.He and his students tied some poles to each of four sides of a 30kilogram stone block. That action turned the block into somewhat a wheel. Then they placed the block on the ground.They wrapped one end of a rope around the bl

18、ock and pulled. The researchers found they could easily roll the block along different kinds of paths. They calculated that rolling the block required about as much force as moving it along a slippery (滑的) path.West hasnt tested his idea on larger blocks, but he thinks rolling has clear advantages o

19、ver sliding. At least，workers wouldnt have needed to carry cattle fat or water to smooth the paths.本文是一篇说明文。古埃及人如何搬运巨石建造金字塔一直是一个谜，不过一项新研究表明，他们有可能是通过在巨石四周捆绑木棒，使其滚动运行这一更加省力的办法来搬运巨石的。5Its widely believed that the stone blocks were moved to the pyramid site by _.Arolling them on roadsBpushing them over

20、the sandCsliding them on smooth pathsDdragging them on some poles答案：C解析：细节理解题。根据第四段第一句“The most popular view is that Egyptian workers slid the blocks along smooth paths.”可知，人们普遍接受的观点是埃及人是在光滑的道路上滑动石块的，故选C项。6The underlined part “lubricated the paths” in Paragraph 4 means _.Amade the paths wetBmade the

21、 paths hardCmade the paths wide Dmade the paths slippery答案：D解析：词义猜测题。由该词组所在句子的后半部分“either with wet clay or with the fat from cattle”可推知，他们使用湿的黏土或牛的脂肪使道路变得光滑，这样才能更轻松地移动石块。7What does the underlined word “it” in Paragraph 7 refer to?ARolling the blocks with poles attached.BRolling the blocks on wooden

22、wheels.CRolling poles to move the blocks.DRolling the blocks with fat.答案：A解析：代词指代题。根据“So he tried it.”中的So一词可判断，it指代的内容应该在第六段。由文章第六段中的“A square could be turned into a rough sort of wheel by attaching wooden poles to its sides.make a block of stone a lot easier to roll than a square”可知，物理学家West提出，在石块

23、四周捆绑上木棒可以使石块更容易滚动。因此他对这种方法进行了尝试，故选A项。8What is the text mainly about?AAn experiment on ways of moving blocks to the pyramid site.BAn application of the method of moving blocks to the pyramid site.CAn argument about different methods of moving blocks to the pyramid site.DAn introduction to a possible new way of moving blocks to the pyramid site.答案：D解析：主旨大意题。文章主要介绍了古埃及人搬运巨石建造金字塔可能用的更省力的办法，故选D项。