每日一练:2021年考研英语二模拟试题(2020-10-10)
发布时间:2020-10-10
2021年考研初试备考还有最后的近三个月时间,相信大家也都在紧张的复习当中。在复习时,多做练习题可以让我们更加了解考试内容。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,正在备考的小伙伴赶紧练起来吧。
SectionB
Directions:In the following article, some sentences have been removed. For
questions41-45, choose the most suitable one from the list A~G to fit into each
of the numbered blank. There are two extra choices, which do not fit in any of
the gaps。(10points)
Researchers have found that drugs used to
treat human seizures can delay aging in worms by as much as 50 percent. The
roundworms used for the study are similar to humans in their molecular makeup,
raising the
possibility that the drugs could also
extend the life span of humans。
41
“By finding a class
of drugs that delays aging we have found a relationship between the function of
the nervous system and aging that was not well understood, ” said Kerry Komfeld, a geneticist at the
Washington
University School of Medicine in St. Louis,
Missouri. The findings are detailed this week in the journal Science。
The discovery came out of the thesis work
by one of Komfeld’s graduate
students, Kimberley Evason. About four years ago, Evason began exposing groups
of the roundworm Caenorhabditis elegans to commercially available drugs to see
if the drugs would delay aging or promote longevity。
42
Over eight months the scientists tested 20
drugs, all with negative results. Finally they tested the anticonvulsant drug
ethosuzimide. Researchers found that the drug extended the life span of
roundworms from 16. 7 days to 19. 6 days, a 17 percent increase。
43
The discovery that the drugs extend the
life span of roundworms could have important implications fox human aging as
well. There are strong similarities on the molecular level between the proteins
and genes that
constitute the worm and those that make up
other animals, including humans。
“Many basic
processes are highly related, including neural function, insulin signaling, and
probably important aspects of the aging process, ” Komfeld said. “There’s every reason to think that these
animals an a good model for higher animals, such as people. ”
44
Ethosuzimide, which was developed in the
1950s, is commonly used to treat epilepsy, though it is no known precisely how
the drug controls convulsions. There is no anecdotal evidence that it has had
an anti-aglng effect in people. The next step, Komfeld says, is to test if the
drugs have an anti-aging effect on animal like flies and mice。
Very little is known about the aging
process. From genetic analysis, researchers have found that an in sulin-like
signaling system regulates aging and longevity. A good diet can delay aging and
extend a person life span. But scientists know virtually nothing about the
effect of drugs on aging. “It’s a big void, ” Konfeld said。
In addition to delaying age-related
degenerative changes, the drugs also increased neuromuscular activty,
suggesting a link between the neuromuscular system and the aging process。
45
There may also be other targets not yet
explored that affect aging and neuromuscular function. Said Kornfeld: “The process of aging remains mysterious. ”
A. But Komfeld said scientists will not
know about the applicability of the drugs in humans until a similar study is
done on humans. “What’s very encouraging is that these drugs
were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。
B. Later the scientists discovered that two
related anticonvulsant drugs also lengthened the lives of the worms-in the case
of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to
aging. That connection was completely unexpected. ”
C. Roundworms are a poor subject for
experiments, because they are not like humans, even though their molecules are
similar. For example, they have no bones, nor do they show emotions, making it
difficult to know how exactly human subjects would react to these drugs in
large quantities. However, using the worms allows experiments to be conducted
quickly, because they do not live for long。
D. “Somehow the neural activity seems to regulate the aging of all of
the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates
the progress of all these tissues, evidently, though the life stages. But we
don’t know how it does
that. ”
E. The discovery may also shed light on the
little-understood aging process. Since the drugs act on the neuromuscular
systems of both humans and worms, the findings hint at a link between neural
activity and aging。
F. Unlike vertebrates, the worms are ideal
subjects for the study of aging because of their short life spans, which last
only a couple of weeks in a laboratory. The worm is well known in genetics, and
the worm’s genome has been
sequenced。
G. Use of this drug has been permitted by
law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human
aging, but we still need to find proof, says Kornfeld optimistically. ”
参考答案及解析
[参考译文]
研究者们最近发现治疗人类突发性疾病的药对于延长人类的寿命也有帮助。研究者们对蛔虫使用了这种药,结果发现蛔虫的寿命增加了50%。使用蛔虫作为研究对象是非常有意义的,因为蛔虫在很多重要方面与人类都颇为相似,尤其是在基因和蛋白质的构成方面。研究中使用的药物已经在人类的实际生活中被使用过了,特别是抗癫痫药。这种药同样也会增加蛔虫的神经肌肉活动,研究者们认为这种活动与延缓衰老同样有着某种联系。
41. [答案]E
[解析]空前文字提出了文章的主题,也就是概括性地介绍了文章的内容:“一项研究表明治疗人类突发性疾病的药物能延缓虫子的衰老,由于人类的分子结构与虫子相似,所以有可能这种药物也能延缓人类的衰老”。只有选项E继续概括性地介绍了文章的内容:“这项研究同样也表明神经肌肉活动与衰老有关系”。
42. [答案]F
[解析]空前文字概括介绍了Evason的实验,只有选项F非常清楚地描述了实验对象,并说明为什么使用这个实验对象的原因。这实际上都是介绍实验的一部分。
43. [答案]B
[解析]空前文字一直提到实验的进程和结果,选项B进一步提到了这次实验的结果。同现原则,这一空的正确选项应该是B。
44. [答案]A
[解析]空前文字提到:“有理由相信这种实验结论对更高级的动物,如人类,也同样适用”。所以这一空应该继续谈到实验结果对人类究竟是不是适用的问题。选项A提到:“但是科学家们目前还不知道究竟对人类是不是适用,除非也在人类身上做相同的实验”。显然,选项A最合适。
45. [答案]D
[解析]空前文字提到了另一个问题:神经肌肉活动与延缓衰老的问题;只有选项D继续提到了这个问题,所以选D。
选项C:该选项指出:“蛔虫实际上并不是理想的实验对象,因为蛔虫不是人类,尽管两者分子结构相同。”显然,这个选项与原文主旨完全背离。连实验对象都是错误的话,文章的结论就更加不可能是正确的。这个选项应该排除。
选项G:该选项指出:“这种药物已经用于延缓人类衰老了,虽然还需要更多的证据来证明这种药物真的会起作用”。这种论点显然是不对的;没有做过实验怎么能够就冒然使用呢?而且与文中提到的“目前还没有在人类身上做实验”这一点完全相左。这个选项也是明显的干扰选项。
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