1、课时跟踪训练21.用括号内所给单词的适当形式填空1His explanation was not_(reason), so all of us didnt accept it.2From the appearance, we can not tell the_(differ) between the twins.3After his_(retire), he settled down in a remote village.4Grey decided to move to the countryside and his mother made no_(object) to it.5What I
2、 want is_ (exact) this one.6We cant_ (undertake) the work for the time being.7It is difficult _(obtain) reliable evidence.8We are playing a trick on a man who keeps _(bother) me.9His own pride_(forbid) him to ask Toms help.10Will they be able_(resist) the temptation to buy?答案1reasonable2.difference3
3、.retirement4objection5.exactly6.undertake7.to obtain8bothering9.forbids10.to resist.阅读理解阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。AThe news that researchers have used cloning to make human embryos for the purpose of producing stem cells may have some people wondering if it would ever be possible to clone a
4、 person. Although it would be immoral, experts say it is likely biologically possible to clone a human being. Since the 1950s when researchers cloned a frog, scientists have cloned dozens of animal species, including mice, cats, sheep, pigs and cows.With mice, researchers are able to use thousands o
5、f eggs, and conduct many experiments, to work out these problems. “Its a numbers game，” said Dr. Robert Lanza, the chief scientific officer at a biotech company. “But with primates (灵长类动物), eggs are very precious, and it is not easy to get them to conduct experiments.”In addition, researchers cant s
6、imply apply what theyve learned from cloning mice or cows to cloning people. Cloning an animal requires that researchers remove proteins that are necessary to help cells divide. In mice, this isnt a problem, because the embryo that is created is able to make these proteins again. But primates arent
7、able to do this, and researchers think it may be one reason that attempts to clone monkeys have failed.Whats more, cloned animals often have different kinds of abnormalities. These abnormities are common because cloned embryos have just one parent rather than two, which means that a process known as
8、 “imprinting (印记)” does not occur properly in cloned embryos.“Problems with imprinting can result in extremely large embryos, which leads to problems with blood flow for the baby，” Lanza said. “The extremely high rate of death and the developmental abnormities from cloning makes cloning people immor
9、al. Its like sending your baby up in a rocket knowing theres a 5050 chance that its going to explode.”1What can we learn from Paragraph 1?AAnimal cloning is illegal.BHuman cloning is possible.CHuman embryos may have new functions.DAnimal embryos can be used for medicine.2How does the author develop
10、Paragraph 2?ABy making comparisons.BBy showing processes.CBy offering analyses.DBy using statistics. 3.How were the experiments on cloning monkeys?AThey have solved the problem with proteins.BThey have been applied to human cloning.CThey were successful.DThey were in trouble.4How does Lanza feel abo
11、ut human cloning?AIt is risky. BIt is practical.CIt is beneficial. DIt is promising.答案与解析语篇导读：本文是说明文。文章介绍了动物克隆及人类克隆面临的难题。1B细节理解题。根据第一段中的experts say it is likely biologically possible to clone a human being可知，人体克隆具有可能性。2A写作手法题。第二段比较了老鼠和灵长类动物做克隆实验的不同点。3D推理判断题。根据第三段中的primates arent able to do this, and
12、 researchers think it may be one reason that attempts to clone monkeys have failed可推断，对猴子进行的实验遇到了困境。4A推理判断题。根据末段中的Its like sending your baby up in a rocket knowing theres a 5050 chance that its going to explode可推断，人体克隆有很大的风险。B(2019年高考课标全国卷I)As data and identity theft becomes more and more common, th
13、e market is growing for biometric(生物测量)technologieslike fingerprint scansto keep others out of private espaces. At present, these technologies are still expensive, though.Researchers from Georgia Tech say that they have come up with a lowcost device(装置)that gets around this problem: a smart keyboard
14、. This smart keyboard precisely measures the cadence(节奏)with which one types and the pressure fingers apply to each key. The keyboard could offer a strong layer of security by analyzing things like the force of a users typing and the time between key presses. These patterns are unique to each person
15、. Thus, the keyboard can determine peoples identities, and by extension, whether they should be given access to the computer its connected toregardless of whether someone gets the password right.It also doesnt require a new type of technology that people arent already familiar with. Everybody uses a
16、 keyboard and everybody types differently.In a study describing the technology, the researchers had 100 volunteers type the word “touch”four times using the smart keyboard. Data collected from the device could be used to recognize different participants based on how they typed, with very low error r
17、ates. The researchers say that the keyboard should be pretty straightforward to commercialize and is mostly made of inexpensive, plasticlike parts. The team hopes to make it to market in the near future.5Why do the researchers develop the smart keyboard?ATo reduce pressure on keys.BTo improve accura
18、cy in typing.CTo replace the password system.DTo cut the cost of espace protection.6What makes the invention of the smart keyboard possible?AComputers are much easier to operate.BFingerprint scanning techniques develop fast.CTyping patterns vary from person to person.DData security measures are guar
19、anteed.7What do the researchers expect of the smart keyboard?A. Itll be environmentfriendly.B. Itll reach consumers soon.C. Itll be made of plastics.D. Itll help speed up typing.8Where is this text most likely from?AA diary. BA guidebook.CA novel. DA magazine.答案与解析语篇导读：这是一篇说明文。数据和身份盗窃变得越来越普遍，目前，像指纹扫
20、描等这些技术仍然是昂贵的。本文介绍了一种新的科技智能键盘，它能给espace用户带来安全，而且这项技术也不贵。5D细节理解题。根据第一段的At present, these technologies are still expensive, though.和第二段的Researchers from Georgia Tech say that they have come up with a lowcost device that gets around this problem: a smart keyboard.可知，研究者们开发智能键盘是为了降低espace保护的成本。故选D。6C细节理解
21、题。根据第二段的The keyboard could offer a strong layer of security by analyzing things like the force of a users typing and the time between key presses.These patterns are unique to each person.Thus，the keyboard can determine peoples identities可知，因为每个人的打字方式不同，使智能键盘能够识别人的身份。故选C。7B细节理解题。根据最后一段的The team hopes
22、 to make it to market in the near future.可知，研究者们希望智能键盘能早日面世。故选B。8D推理判断题。本文介绍了一种新的科技智能键盘，它能给espace用户带来安全，由此可知，本文是关于科技，结合所给选项可知，本文可能来自于一本杂志。故选D。CWhen I went away to college, I chose to go to a large school in another state in an attempt to never again see those popular girls, the ones who drove quiet
23、girls like me headlong into the arms of dusty books. Since I didnt know a soul at this university, I volunteered for a club to make friends. Thats how I ended up one winter evening standing outside the student union, waiting for the nights famous speaker to drive up. My assignment was to escort (护送)
24、 her to the auditorium where her fans eagerly waited to hear Maya Angelou, author of I Know Why the Caged Bird Sings. As showtime neared, Angelous car pulled up. When its door opened, Angelou and a female friend exited, each wearing headtotoe fur coats. I nervously guided the pair inside. Angelou wa
25、s ready to sweep onstage, but first, there was her fur coat. I offered to babysit it backstage to make sure it was safe. “No, ” she said. She looked out at the audience. “You need to get out there and live. ”So I found a frontrow seat and heard, for the first time, a book come alive in an authors ow
26、n voice. The audience clapped and cheered as they went along on the ride of this performance.I wish I could say that my life changed then. But out of college, I went deeper into my interior self, taking a job that required little human contact. A few years later, I became a newspaper editor, which r
27、equired talking to many people. For those times, I depended on index (索引) cards. But I reminded myself that Angelou hadnt used notes. Today, Im in my 50s. I am speaking comfortably about what I really know to be true. I get out there now and live.9What kind of person did the author use to be? ABrave
28、. BKind.CCareless. DShy.10Why did Angelou decline the authors offer to take care of her fur coat? AShe wouldnt trust a stranger with it. BShe thought it was the duty of her assistant. CShe wanted the author to enjoy the performance. DShe thought it was safe enough to put it backstage. 11Soon after g
29、raduating from college, the author_. Afound a job as a newspaper editorBkept shutting herself in her own worldCchanged a lot under Angelous influenceDfelt more confident when speaking in public12What would be the best title for the text? AGet Out There and LiveBThe Night I Met AngelouCSpeak from You
30、r Inner SelfDMy Friendship with Angelou答案与解析语篇导读：作者讲述了一位著名的演说家所说的话和表演对自己的深远影响。9D推理判断题。根据第一段的“never again see those popular girls, the ones who drove quiet girls like me”可推测， 作者应该是个比较腼腆的女孩。10C推理判断题。根据第三段Angelou所说的话“You need to get out there and live.”和下文作者在观众席坐下来可知， Angelou希望作者把时间用在该用的地方， 应该去看表演而不是看衣服。11B细节理解题。根据倒数第二段的“I wish I could say.human contact.”可知， 作者刚毕业时， 并未因Angelou的话而改变， 还是把自己封闭起来。12A标题归纳题。根据第三段Angelou所说的话“You need to get out there and live.”和文章结尾“I get out there now and live.”可知， A项作标题表现出Angelou对本文作者的影响以及作者自身的改变， 非常贴切。