考前必看:2021年考研英语工学类阅读理解模拟题及答案(二十七)

发布时间:2020-10-12


最近,有小伙伴在询问最后阶段,考研英语该如何备考才最有效。最后阶段,我们应该将备考的重点放在复习和了解考试上,多去练习历年真题和模拟试题。下面,51题库考试学习网为大家带来考研初试的一些模拟试题,一起来看看吧。

Hauling yourself up by the bootstraps has never been easy. But computers do this every time they are turned on-hence the verb "to boot". Booting a computer takes valuable time, compounded by the rebooting that is inevitably necessary whenever a computer freezes.

The reason that this process takes so long is that a computer\'s operating system must be loaded from its hard disk into its random-access memory (RAM) every time the machine is turned on. Unlike magnetic tapes or hard disks, RAM is an electric form of memory. It is, in effect, an array of tiny capacitors which, when charged, represent a binary "1" and, when not charged, represent a binary "o". This has allowed them to be much faster than magnetic memory, in which the binary digits ("bits") are represented by magnetically polarised regions rather than electric charges. The big problem with electric memory, however, is that it is volatile-the capacitors have to be recharged frequently so that they can continue to remember a"1". When a computer is turned off, they lose all the data stored in them.

The race has been on to build nonvolatile high-speed memories that will allow computers to be turned on and off like televisions. Whichever technology wins is almost certain to be used in all new computers, so the stakes are high. Motorola, IBM, and Hewlett-Packard are all developing magnetic RAM (MRAM) which seems poised to become the nonvolatile technology of choice. Both Motorola and IBM have announced plans to bring the technology to market within 18 months, advancing their initial target date of 2004. Besides turning instantly on, computers equipped with such chips would consume less power, making the technology ideal for satellites and portable gizmos.

MRAM works by etching a grid of criss-crossing wires on a chip in two layers-with the horizontal wires being placed just below the vertical wires. At each intersection, a "magnetic tunnel junction" (MTJ) is created that serves as a switch-and thus as a repository for a single bit of memory. The MTJ is essentially a small magnet whose direction is easily flipped. Common materials for the MTJ include chromium dioxide and iron-cobalt alloys.

Earlier this year, Motorola unveiled a prototype MRAM chip that stores 256 kilobits and has a cycle time for reading and writing data of less than 50 nanoseconds (billionths of a second). That puts it in the same league as conventional dynamiC-RAM (DRAM) chips. IBM, collaborating with Germany\'s Infineon Technologies, has developed a one megabit (million bit) MRAM chip at its laboratories in East Fishkill, New York.

There is still a long way to go before MRAM is ready for prime time. Neither IBM nor Motorola, for instance, is expected to go into mass production until they prove that they can make 256 megabit chips-the standard memory module used today. But, as total sales of computer memory in 2000 were estimated by Semico Research Corporation to have been worth $48 billion, manufacturers have a considerable incentive to ensure that MRAM becomes a serious challenger for DRAM\'S crown.

(1):本文选自Economist; 9/22/2001, p8, 1/3p;

(2):本文习题命题模仿对象2004年真题Text 3;

1. By the word volatile(Line 7, Paragraph 2), the author means _________.

[A]difficult to start.

[B]slow running.

[C]time-consuming.

[D]easy to lose data.

2. How does the author feel about the future of MRAM?

[A]Optimistic.

[B]Discouraging.

[C]Confused.

[D]Indifferent.

3. When mentioning the stakes are high(Line 3, Paragraph 3) the author means

___________.

[A]the risks are very high

[B]the payments are very good

[C]the applications are very wide

[D]the users are very satisfied

4. Why are Motorola, IBM, and HP all developing MRAM?

[A]they are most likely to have big profits.

[B]there is a severe competition among them.

[C]turning-on computer takes too much time for their users.

[D]the working speed of the computer is so slow.

5. Which of the following is not the characteristic of the computer equipped with MRAM?

[A]instant turning-on and turning-off.

[B]less consumption of power.

[C]huge memory module

[D]lasting stored data.

答案:DABAC

篇章剖析

本文是一篇说明文,文章主要介绍了能够达到瞬间开机的磁存储器的开发原因、运做原理以及具体的研究及开发情况。第一段指出开机和关机花费时间;第二段分析其原因,把电存储器和磁存储器进行了对比;第三段指出这种磁存储器的性能优势;第四段指出磁存储器的运做原理;第五段指出这种磁存储器的最新开发情况;最后一段指出磁存储器的发展前景。

词汇注释

poise [pCiz] vt. 使(重量)相等, 使(保持)平衡, 使悬着;(投标枪一样的)姿势; 使(头等)保持一定姿势[位置];仔细考虑; 使作好准备;使悬而不决, 犹豫, 踌躇

DRAM (Dynamic Random Access Memory的缩写)动态随机存取存储器;[动态随机接达记忆器]

a run for ones money [] 1. 激烈的竞争2. 出了钱(或力)而得到的满足

haul [hC:l] vt. , , ;硬拖;强迫做硬拖强拉(特别用于审讯)

bootstrap [5bu:tstrAp] n. 引导程序;自举技术[设备];【动】自举,引导;[靴带式;启动程序]

boot [5bu:t] vt. n.启动,引导

compound[5kRmpaJnd]v.使增加;增加

reboot [ri:5bu:t] vt. n. 重新启动,重新引导

RAM=Random Access Memory 随机存取存贮器

volatile [5vClEtail] adj. (液体等)挥发(), 易发散的;轻快的, 轻浮的;易变的, 短暂的; 非永久性的;易失的(电源切断后信息消失); 反复无常的

stake [steik] n. [pl.] 赌物; 赌金;[pl.]奖金[];利害关系, 风险;(下在投机生意上的)股本[]

of choice优先选择的,在同一类或同一组中比别的更受欢迎的,精选的

gizmo n. 小发明,新玩艺儿,小物件(忘记了名字、不知道名称或不道出名称时使用的词)

grid [^rid] n. 格栅, 格子;【电】(蓄电池中的)铅板;【无】栅极

etch [etF] vt, vi. (常与on, upon连用)(用酸在金属上)蚀刻

criss-crossing n. 十字交叉形

magnetic tunnel junction (MTJ) 磁隧道结

repository [rI5pRzItErI; (?@) -tC:rI] n. 贮藏室, 智囊团, 知识库, 仓库

flip vi.【非正式用语】翻转,颠倒;突然转向

chromium dioxide 二氧化铬

Iron-Cobalt alloy铁钴合金

prime time n. 黄金时段,黄金时间(通常指晚间七时至11时电视观众最多的时段)

难句突破

Booting a computer takes valuable time, compounded by the rebooting that is inevitably necessary whenever a computer freezes.

主体句式:Booting a computer takes time

结构分析:本句是一个简单句。现在分词短语“booting a computer”做句子主语;compounded”之前省去了“which is;by”的成分是伴随状语;that”引导定语从句来修饰“rebooting;whenever”引导时间状语从句。

句子译文:启动计算机要花费宝贵时间,但每当计算机死机后,重新启动又是不可避免、绝对必要的,这就更花时间。

题目分析

1.答案为D,属猜词题。这是一个在文中出现频率较高的单词。第一段指出开机和关机花费时间;第二段分析其原因,把电存储器和磁存储器进行了对比:电存储器比磁存储器快,但是它的缺点是“it is volatile”,句子“When a computer is turned off, they lose all the data stored in them.”是对这个单词做出的解释。

2. 答案为A,属情感态度题。原文对应信息是“But, as total sales of computer memory in 2000 were estimated by Semico Research Corporation to have been worth $48 billion, manufacturers have a considerable incentive to ensure that MRAM becomes a serious challenger for DRAM\'S crown.

3. 答案为B,属推理判断题。无论哪种技术取胜,该技术肯定会在所有新计算机里被采用,而且据Semico市场调研公司估计,2000年电脑内存的总销售额是480亿美元,因此对于制造商来说,这是相当大的刺激因素来保证使MRAM成为代替DRAM的一个真正的挑战者。

由此,我们可以说回报是相当高的。

4. 答案为A,属事实细节题。原文对应信息是“But, as total sales of computer memory in 2000 were estimated by Semico Research Corporation to have been worth $48 billion, manufacturers have a considerable incentive to ensure that MRAM becomes a serious challenger for DRAM\'S crown.

5. 答案为C,属事实细节题。从句子“Neither IBM nor Motorola, for instance, is expected to go into mass production until they prove that they can make 256 megabit chips-the standard memory module used today.”我们知道现在这些公司还不能生产出比标准模块更大的内存模块,因此选项C是不对的,其它选项在文中都可找到对应信息。

以上就是51题库考试学习网为大家带来的全部内容,希望能给大家一些帮助。51题库考试学习网提醒:2021年考研正式报名已经开始,在预报名阶段未来得及报名的小伙伴要注意了。另外,小伙伴们如果还有其他关于考研信息的疑问,也可以留言咨询哦。


下面小编为大家准备了 研究生入学 的相关考题,供大家学习参考。

下列有关原核生物DNA聚合酶I的叙述,的是


A.其在复制过程中起校读、填补空隙的作
B.有5'—3'聚合酶活性
C.有3,—5'外切酶活性
D.无5'—3'外切酶活性
答案:D
解析:
[考点]DNA复制及复制的酶[分析]DNA聚合酶I具有5'→3'聚合酶活性,但其仅能催化约20个核苷酸聚合,故它不是真正在复制延长中起作用的酶,只能填补空隙。但DNA聚合酶I的3'—5'外切酶活性较强,在5'—3'聚合酶活性配合下可完成即时校读。DNA聚合酶I还具有5'—3'外切酶活性,是切除引物、切除突变片段功能所需的,故D是错误的。此酶属依赖DNA的DNA聚合酶。

热激蛋白(热休克蛋白)的生理功能

A.作为酶参与蛋白合成
  B.促新生多肽链折叠
  C.参与蛋白靶向运输
  D.肽链合成起始的关键分子
答案:B
解析:

急性肾小管坏死时肾血流动力学异常表现为
A.内皮素产生过少 B.血栓素A2产生过少C. NO合成减少 D. PGE2合成过多

答案:C
解析:
急性肾小管坏死时肾血流动力学异常主要为肾血浆流量下降,肾内血流重新分布,其主要机制为肾内肾素-血管紧张素系统兴奋,血管收缩因子(内皮素、血栓素A2)产生过多,而血管舒张因子(NO、 PGE2)产生相对过少。

41岁农村母亲,目睹其犯罪儿子在家中被警察带走,突然抽搐发作,但无意识丧失、咬舌、严重摔伤或小便失禁,这是( )

A.苯丙酮尿症
B.急性应激障碍
C.癔症性躯体障碍
D.创伤后应激障碍
答案:C
解析:
癔症性躯体障碍。 癔症性躯体障碍也称为转换性障碍,通常是指身体机能发生障碍,比如瘫痪、麻痹、抽搐、失明、失聪等。因此C选项正确。急性应激障碍,也叫急性应激反应,是由剧烈的、异乎寻常的精神刺激、生活事件或持续困境的作用下引发的精神障碍。多数病人发病在时间上与精神刺激有关,症状与精神刺激的内容有关,其病程与预后也与及早消除精神因素有关。苯丙酮尿症是一种先天性疾病主要症状是生长发育迟缓、智力低下。

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