题目
题型:不详难度:来源:
The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the colour of a dark-striped zebrafish to uniform gold by inserting a version of the pigment(色素) gene into a young fish. As with humans, zebrafish skin colour is determined by pigment cells, which contain melanosomes(黑色素). The number, size and darkness of melanosomes per pigment cell determines skin colour.
It appears that, like the golden zebrafish, light-skinned Europeans also have a mutation(变异) in the gene for melanosome production. This results in less pigmented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.
Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun(太阳光紫外线), which can cause skin cancer.
But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.
Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin colour, said Cheng.
The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment did on Michael Jackson.
51. The passage mainly tells us that ________.
A. people can not change their skin colour without any pain
B. the new discovery could lead to search into ways to change skin colour safely
C. pop king Michael Jackson often changed his skin colour as he liked
D. scientists have found out that people’s skin colour is determined by the gene
52. It can be inferred from the passage that ________.
A. nowadays people who want to change their skin colour have to suffer a lot from the damage caused by the chemical treatment
B. Europeans and Africans have the same gene
C. the new discovery could help to find medical treatments for skin cancer
D. there are two kinds of genes
53. Scientists have done an experiment on a dark-striped zebra fish in order to ________.
A. find the different genes of humans’
B. prove the humans’ skin colour is determined by the pigment gene
C. find out the reason why the Africans’ skin colour is dark
D. find out the ways of changing peopl’s skin colour
54. The reason why Europeans are light-skinned is probably that ________.
A. they are born light-skinned people
B. light-skinned Europeans have mutation in the gen for melanosome production
C. they have fewer activities outside
D. they pay much attention to protecting their skin
55. The writer’s attitude towards the discovery is ________.
A. neutral B. negative C. positive D. indifferent
答案
C 篇:本文主要讲述基因决定人的肤色。
51. D
52. A
53. B
54. B
55. C
解析
51. D 主旨大意题 根据全文讲述的主要内容得知:科学家们发现人的肤色是由基因决定的。
52. A 推理判断题 从文章最后一句话得知,人们改变肤色会象迈克尔·杰克逊那样受到化学药品对皮肤的伤害。
53. B 细节理解题 根据第三段得知,因为斑马鱼和人类一样肤色中含有黑色素,所以科学家们以此来证明之。
54. B 推理判断题 根据第四段得知,因为欧洲人体内黑色素的基因发生了变异,所以他们的皮肤为浅肤色。
55. C 推理判断题 根据作者对基因决定人的肤色的论述以及文章首尾段可知,作者对此的态度是肯定的。
核心考点
试题【Can people change their skin colour without suffering like pop king Michael Jack】;主要考察你对题材分类等知识点的理解。[详细]
举一反三
Mice will probably 21 sing their way to any concert, but researchers in the United States have found 22 that mice do, 23 , sing.
Scientists already knew that mice make ultrasonic(超声波) sounds—noises that are too high-pitched(高音的) for people to hear 24 special equipment.
To find out whether mice put such sounds together in song-like 25 , the researchers recorded the sounds of 1 mice. Using computer 26 , they were able to separate the sounds into specific types of syllables(音节), and found the mice produced about 10 syllables per second.
The results showed that nearly all of the mice repeated sequences(顺序) of syllables in different patterns. That’s enough to meet the definition of what scientists 27 song. But not all scientists are 28 _ that what the mice are doing is 29 singing. To prove it, the researchers must show that there’s learning involved. And, they need to __ 30 why the mice sing.
21. A. almost B. even C. never D. usually
22. A. coincidence B. evidence C. guidance D. instance
23. A. at once B. by means C. for example D. in fact
24. A. during B. inside C. through D. without
25. A. fashions B. instructions C. patterns D. styles
26. A. access B. printer C. screen D. software
27. A. call B. hear C. sing D. write
28. A. accustomed B. convinced C. involved D. qualified
29. A. actually B. obviously C. simply D. unlikely
30. A. figure out B. get about C. run across D. talk over
What made him sad was __22__ his piano teacher in Beijing didn’t like him. “You have no talent. You will never be a pianist.” As a nine-year-old boy, Lang Lang was badly __23__. He decided that he didn’t want to be a pianist any more. For the next two weeks, he didn’t touch the piano. Wisely, his father didn’t push, but waited.
Luckily, the day came when his teacher asked him to play some holiday songs. He didn’t want to, but as he placed his fingers on the piano keys, he __24__ that he could show others that he had talent __25__. That day he told his father what he had been waiting to hear—that he wanted to study with a new teacher. From that point on, everything turned around.
He started __26__ competitions. In the 1994 International Young Pianists Competition, when it was __27__ that Lang Lang had won, he was too excited to hold back his tears. Soon __28__ was clear that he couldn’t stay in China forever—he had to play on the world’s big stages. In 1997 Lang Lang moved again, this time to Philadelphia, USA. There he spent two years practicing, and by 1999 he had worked hard enough for fortune to take over. After his __29__ performance at Chicago’s Ravinia Festival, gigs in Lincoln Centre and Carnegie Hall started __30__ in, Lang Lang finally worked to reach the place where fortune spots him, and lets him shine.
21. A. exercise B. fortune C. knowledge D. wealth
22. A. whether B. why C. when D. that
23. A. hurt B. weakened C. ruined D. frightened
24. A. seemed B. admitted C. noticed D. realized
25. A. in all B. above all C. after all D. at all
26. A. receiving B. accepting C. winning D. beating
27. A. told B. mentioned C. announced D. recognized
28. A. this B. it C. that D. what
29. A. successful B. cheerful C. respectful D. meaningful
30. A. pulling B. breaking C. falling D. pouring
Yet despite that, reading is increasingly unpopular among children .According to statistics in 1997, 23% said they didn’t like reading at all.In 2003, 35% didn’t.And around 6% of the children leave primary school each year unable to read properly.
Maybe the decline is caused by the increasing availability of computes games.Maybe the books boom has affected only the top of the educational pile.Either way, Chancellor Cordon Brown plans to change things for the bottom of the class .In his pre-budget report, he announced the national project of Reading Recovery to help the children struggling most.
Reading Recovery is aimed at six year olds, who receive four months of individual daily half-hour classes with a specially trained teacher.An evaluation this year reported that children on the school made 20 months’ progress in just one year, whereas similarly weak readers without special help made just five months’ progress ,and so ended the year even further below the level expected for their age.
International research tends to find that when British children leave primary school, they read well ,but read text often for fun than those elsewhere .Reading for fun matters because children who are keen on reading can report lifelong pleasure and loving books is an excellent indicator of future educational success .According to the OECD, being a regular and enthusiastic reader is of great advantage.
51.Which of the following is true of Paragraph 1?
A.Many children’s books have been adapted from films.
B.Many high-quality children’s books have been published.
C.The sales of classics have led to the popularity of films.
D.The sales of presents for children have increased.
52.Statistics suggested that .
A.the number of top students increased with the use of computers
B.a decreasing number of children showed interest in reading
C.a minority of primary school children read properly
D.a huge percentage of children read regularly
53.What do we know about Reading Recovery?
A.An evaluation of it will be made sometime this year.
B.Weak readers on the project were the most hardworking.
C.It aims to train special teachers to help children with reading.
D.Children on the project showed noticeable progress in reading.
54.Reading for fun is important because book-loving children _________.
A.take greater advantage of the project
B.show the potential to enjoy a long life
C.are likely to succeed in their education.
D.would make excellent future researchers
55.The aim of this text would probably be _________.
A.to overcome primary school pupils reading difficulty.
B.to encourage the publication of more children’s books
C.to remind children of the importance of reading for fun
D.to introduce a way to improve early children reading
As she waited at the edge of the ice for her music to start,. Peggy took a quick look at her father standing nearby with a group of parents and teachers. He smiled at her. Then she 1._____ out at the audience, 2._____ to see her mother. These two, Alvert and Doris Flemint, had 3._____ all the way from California more than 2,000 miles away, to see their 4._____ compete in this sports meet in Cleveland, Ohio.
The music 5._____ and Peggy moved onto the ice, letting the music 6._____ her along into her turns, and she began skating with much 7._____ in herself. The cold fear she always had in the 8._____ seconds before skating onto the ice was 9._____. She was feeling the movement of the 10._____ and letting it carry her. She skated easily, 11._____ did some jumps, a final turn and her performance was 12._____.
The crowd loved it and cheered 13._____ she skated off the ice. “Nice job,” said one of the other 14._____. It was the remark that 15._____ came after a free-skating performance. But what should the 16._____ say? Standing beside her father, Peggy 17._____ for the scoring to be finished. On all sides were other young skaters, some waiting 18._____ alone, others with a parent. Shortly before 10 o’clock the results were 19._____. The new United States Women’s Figure Skating Champion was Peggy Fleming of Passdena, 20._____.
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In the United States there was an unusual tale telling of the daughter of a mechanic (技工). One day while walking along the bank of a lake, the girl 36 to see 20 eggs laid by a wild goose. After some time the girl 37 the mother would not return to her eggs and she 38 to take them home. There she carefully 39 the eggs in the heat of a lamp. Several days 40 the eggs broke and the baby geese came into the 41 .
Geese are known to take the first living thing they see as their mother. 42 , to these young geese, the girl was their mother.
As they 43 , the girl was able to 44 her birds to run across the grass, but she could not teach them to 45 . The girl became increasingly worried about this, both when 46 and in her dreams. Later, she had an 47 : She would pilot a plane to guide them in 48 . She asked her father for a plane and he assembled(组装)a small aircraft for her.
Caring about 49 safety, the father decided to pilot the plane himself. However, the birds did not 50 or follow him, and 51 slept in the grass.
One day, the girl 52 into the plane, started it and soon left the 53 . Seeing their mother take to the air, the birds 54 flapped(拍打)their wings and 55 . She flew the plane freely in the sky, her young birds following.
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