Bats are the only mammals that can fly a great distance, but they have another ability. Many bats live a very long time for an animal their size.
European researchers are studying bats to understand why they live so long. They hope to make discoveries to fight the aging process (過程) in human beings.
Last week, the group of scientists said they had found important biological qualities in some bat species. The group studied bat chromosomes (染 色 體), a line of genes found in the nucleus(核) ofcells. The scientists were most interested in parts connected to the ends of the chromosomes. They are called telomeres(端 粒). Telomeres protect the ends of chromosomes, which shorten each time a cell divides. Scientists believe this shortening process causes cells to break down. .
A report on bats was published this month in the journal Science Advances.
Among the leaders of the study was Emma Teeling, a biologist with University College Dublin in Ireland. Teeling said studying long-living mammals that have developed ways to fight aging “is another way to prove the molecular(分 子) basis of extended ‘health length.’” She added that studying bats made scientists able to learn more about the processes “that drive healthy aging.”
The European researchers studied 493 bats from four bat species. The group used information that had been gathered over more than 60 years. Of these animals, the greater mouse-eared bat generally lived the longest, an average of 37 years.
The scientists said this and a related species, which are grouped together under the name Myotis, had telomeres that did not shorten with age. Another Myotis bat holds the record for oldest age, reaching 41 years.
The scientists’ findings suggest that these bats’ cells have the ability to keep and repair their telomeres. This, they said, helps guard against the aging process. Based on its body size, a bat like the greater mouse-eared bat would be expected to live four years. But, these mammals have been found to live nearly 10 times longer than that.
The scientists found that Eighteen of these are bats. The only exception is an unusual African rodent, the naked mole rat.
1.Which sentence can be put at the end of Paragraph 3?
A. This makes scientists able to study bats.
B. That’s why bats can fly a great distance.
C. They say this is what causes aging.
D. They discover the cells connected to humans.
2.Why do some species of bats live a very long time?
A. Because they have a line of long-living genes out of the cells.
B. Because their cells have the ability to keep and repair their telomeres.
C. Because they have another ability to live longer without any food or water.
D. Because telomeres protect the ends of chromosomes to stop cells dividing.
3.The underlined word “that” refers to .
A. four years B. body size C. the aging process D. the ability to repair
4.What’s the best title of the passage?
A. Differences Between Long-Living Animals
B. A Science Report on Chromosomes
C. Do Bats Hold the Secret to Long Life?
D. Are Humans and Bats Similar in Protecting Themselves?
1.C 2.B 3.A 4.C 【解析】文章講述了螞蟻是個長壽的動物的事情。 1.根據(jù)Scientists believe this shortening process causes cells to break down可知這就是引起老化的東西;故選C 2.根據(jù)The scientists’ findings suggest that these bats’...科目:初中英語 來源:山東省威海市2018年中考英語試卷 題型:閱讀判斷
閱讀C篇,判斷正(A)誤(B)。請將答案編號涂卡。A表示正確,B表示錯誤。
Bangladesh (孟加拉)is an agricultural country between India and Burma. Storms from the
Indian Ocean sweep across the country every year, and large areas of farming land are flooded(沖毀). The people are very poor.
Fewer than half of the country’s children complete their primary education. When they are six or seven years old, many children leave school to work in the fields or at home. The rest of their "education" consists of looking after cattle, collecting firewood or doing household jobs.
Not long ago, an experimental school was opened near the capital, Dacca, to help poor children. There are only 120 children in the school, which has three classrooms. In each class, forty pupils are divided into four groups of ten. Each pupil is free to decide which group he or she wants to join.
The most able pupils do a great deal of the teaching. They act as group monitors. Their duty is to ensure that all pupils in their group understand and practice what the teacher has taught.
There are a number of unusual features in the Bangladesh school. Children do not move up a class automatically when they grow older. Each group is promoted (升級)only when EVERY pupil in it has succeeded in getting to the right standard. As a result, all members of a group work hard to help the less able pupils. Nobody is left behind.
Lessons are extremely practical and include work on farming, carpentry, health and running a home, as well as lessons on the basic skills of reading, writing and arithmetic. At school, pupils prepare for adult life by learning to carry out almost all the tasks which they will face when they grow older.
If pupils have to look after cattle or young children, they are allowed to bring them to school. If a child has to stay at home to help his parents, there is no scolding or punishment (責罰) at school. Children enjoy their lessons and the school is cheap to run. It is so successful that other schools in Bangladesh are beginning to imitate (模仿) its methods. Visitors are even coming from other agricultural countries to see if they can use a similar method.
1.Many people in Bangladesh work on farms
2.Most children in Bangladesh complete their primary education
3.In each group, the biggest or oldest pupil is made a monitor.
4.At the end of each school year, all the pupils move to a higher class
5.At school, pupils learn to do almost all the tasks needed in adult life
1.A 2.B 3.B 4.B 5.A 【解析】短文大意:孟加拉是印度和緬甸之間的農(nóng)業(yè)國。每年的風暴會使大片農(nóng)田被洪水淹沒。因此人民很窮。只有不到一半的兒童會完成小學教育。在學校里實行小組化教學,那些有能力的學生可以擔當班長,負責他們小組內(nèi)的所有學生都能理解和實踐老師所教的內(nèi)容。在學校里他們會學到成人生活所需要的幾乎所有的能力。 1.根據(jù)短文的第一段Bangla...查看答案和解析>>
科目:初中英語 來源:重慶市2018年中考英語試卷 題型:材料作文
書面表達。
假如你是李華,你校正舉辦英語讀書節(jié)活動,你在參與活動的過程中遇到一些困難。請給你的英國朋友Nick寫一封email向他求助。
要求:
1.80—120詞,開頭和結尾已給出,不計入總詞數(shù);
2.文中不能出現(xiàn)自己的姓名和所在學校的名稱。
參考要點:
1.活動情況簡介(時間、內(nèi)容……);
2.遇到的困難(如:缺少相關書籍、英語閱讀困難……);
3.請求幫助的事項。
Dear Nick,
How’s everything going?
Yours,
Li Hua
Dear Nick, How’s everything going? Our school is holding an English reading festival this June. I’m very interested in it. There are many different activation in the festival such as reading goo...查看答案和解析>>
科目:初中英語 來源:重慶市2018年中考英語試卷 題型:單選題
I can’t hear the teacher with so much noise outside.
A. clearly B. slowly C. warmly D. bravely
A 【解析】句意:外面的噪音太大,我聽不清老師的話?疾楦痹~辨析題。A. clearly清晰地;B. slowly緩慢地;C. warmly熱烈地;D. bravely勇敢地。根據(jù)句意語境,可知clearly符合句意,故選A。查看答案和解析>>
科目:初中英語 來源:重慶市2018年中考英語試卷 題型:單選題
I had egg and some milk for breakfast this morning.
A. a B. an C. the D. /
B 【解析】句意:今天早上我吃了一個雞蛋喝了一些牛奶。考查冠詞辨析題。a是不定冠詞,泛指,一個,用于輔音因素開頭的單數(shù)可數(shù)名詞前;an不定冠詞,泛指,一個,用于元音因素開頭的單數(shù)可數(shù)名詞前;the定冠詞,特指,用在獨一無二名詞前,像地球,月亮,太陽。句中egg以元音音素開頭,需用an。根據(jù)句意語境,可知選B。查看答案和解析>>
科目:初中英語 來源:2018年江蘇省連云港市中考英語試卷 題型:單選題
—Could you help me carry the equipment to the basketball field, Robin?
— .I’ll do it at once.
A. Not at all B. No problem C. Wait a moment D. That’s right
B 【解析】句意:——您能幫我把這些器材搬到足球場嗎,羅賓?——沒問題,我馬上做它。 A. Not at all 不客氣; B. No problem沒問題; C. Wait a moment 等一下; D. That’s right那是對的;根據(jù)Could you help me carry和I’ll do it at once.可知是沒問題;故選B查看答案和解析>>
科目:初中英語 來源:2018年江蘇省連云港市中考英語試卷 題型:單選題
National Treasure quickly rose to the top television rating ranks after it was presented on CCTV. It means a growing in traditional culture among China’s youth.
A. interest B. direction C. habit D. dream
A 【解析】句意:《國寶》在電視上播出后,很快上升到電視排行榜榜首,它意味著在中國年輕人中對傳統(tǒng)文化越來越感興趣。A. interest 興趣; B. direction 方向; C. habit 習慣; D. dream夢想;根據(jù)National Treasure quickly rose to the top television rating ranks after it was pr...查看答案和解析>>
科目:初中英語 來源:山西省2018屆九年級中考模擬英語試卷 題型:單選題
-I’ll never forget the years I lived on the farm with the farmers.
-It must have a great effect on your life.
A. when B. that C. which D. in which
A 【解析】句意:——我永遠不會忘記我和農(nóng)民一起在農(nóng)場里生活的那些年。——它一定對你的生活有很大的影響?疾槎ㄕZ從句。先行詞the years是時間,需用when做引導詞。根據(jù)句意結構,可知選A。查看答案和解析>>
科目:初中英語 來源:八年級下 Unit 6 An old man tried to move the mountains.測試卷 題型:單選題
(題文)He asked me whom I ________ for.
A. am waiting B. wait C. will wait D. was waiting
D 【解析】 句意:他問我在等誰?這是賓語從句的結構,當主句是過去時態(tài)時,從句用過去的某一個時態(tài),根據(jù)句意可知這里用進行時態(tài);故選D。查看答案和解析>>
湖北省互聯(lián)網(wǎng)違法和不良信息舉報平臺 | 網(wǎng)上有害信息舉報專區(qū) | 電信詐騙舉報專區(qū) | 涉歷史虛無主義有害信息舉報專區(qū) | 涉企侵權舉報專區(qū)
違法和不良信息舉報電話:027-86699610 舉報郵箱:58377363@163.com