第1题
第2题
A.speculate
B.estimate
C.evaluate
D.anticipate
第3题
A.speculate
B.estimate
C.evaluate
D.anticipate
第4题
Unlocking the Human Genome(基因组)
1 A project to unlock secrets-what scientist could resist that challenge? This is what many scientists are doing as they work on the Human Genome Project. The aim of the project is to decode(破译)all of the some 100, 000 genes in the human body. Scientists are using DNA fingerprinting techniques to do the decoding.
2 DNA is the substance found in the chromosomes(染色体)of a cell. A chromosome is a chain of genes. Each gene carries a piece of genetic information. At any one moment in a cell, thousands of genes are turned on and off to produce proteins(蛋白质). The challenge for scientists is to find out what role each gene plays in protein production. At some point this decoding will be complete. Then scientists will have a map of an ideal genome, or a picture of the total genetic nature of a human being. The ideal genome is called a consensus(交感)genome. Everything works well in a consensus genome.
3 But no one in the world has a consensus genome. Everyone's genome is different from the ideal. These differences are referred to as genetic mutations(突变). Genetic mutations in a person's genome mean that the person has a greater than average chance of suffering from health problems. Some problems are not life-threatening. These would include things like colorblindness, or mild headaches. Other problems are serious, such as heart disease, or cancer.
4 It will take years to identify the role of each of the 100, 000 genes, The short-term goal of the project is to find the physical and mental health problems a person is likely to encounter during his or her lifetime. The long-term goal is to have each person live a longer, healthier life.
A. How does DNA work?
B. What is the Human Genome Project about?
C. How are the DNA samples collected?
D. What are the goals of the Human Genome Project?
E. What is the role of each gene?
F. What are the consequences of genetic mutations?
Paragraph 1 ______
第5题
Heredity(遗传) is not the only thing that influences our color. Where we live and how we live after we are born are important too. For instance, our genes influence how fat or thin we are. But our weight depends mainly upon how much we eat and how much exercise we get. In the same way, our skin color depends to a large extent upon how much sunshine we get.
When summer arrives and light—colored people go to the beaches, some will tan darkly, some will tan lightly and few will not tan at all. Each one has inherited a different ability to tan, but the differences do not appear until the conditions are right. An outdoor man will soon become pale if he changes to an indoor job, while a desk clerk will take on tan after a short vacation in the sun.
Sometimes people decide that being tanned is better than being pale. Sometimes they decide the opposite.
Centuries ago, most of the people in Europe were peasants and they had to work in the fields all day. Noblemen, on the other hand, did not have to work. They stayed indoors and remained pale. You could always tell a nobleman from a peasant because a peasant had a tan. As a result, a shin so pale that the veins (血管) showed was considered a mark of great beauty.
During the Industrial Revolution things changed. Farmers left their fields and went to work in factories, mines and mills. Working for long hours in dimly—lit factories and mines made their skins pale. (77) Wealthy people, however, could afford to travel so sunny countries. They had the leisure to lie around on the beaches and get tan. Having a tan became a sign of wealth.
In Western Europe and North America pale skin is no longer desirable. Instead of bleaching themselves white with lemon juice, many women spend their time under a sun—lamp. The desire for a quick tan has led to the invention of pills and lotions (涂剂) that darken the skin artificially without exposure to sunlight. These pills and lotions can be bought by anyone at any drugstore. A rich man can spend hundreds of dollars on a vacation in the sunny West Indies and get his suntan there. But his lowest—paid clerk can have what looks like the same tan out of a bottle for a few cents.
Besides genes, our skin color has much to do with ______.
A.exercise
B.weight
C.food
D.sunshine
第6题
【C1】
A.that
B.like
C.if
D.as
第7题
Heredity (遗传) is not the only thing that influences our color. Where we live and how we live after we are born are important too. For instance, our genes influence how fat or thin we are. But our weight depends mainly upon how much we eat and how much exercise we get. In the same way, our skin color depends to a large extent upon how much sunshine we get.
When summer arrives and light-colored people go to the beaches, some will tan dark-ly, some will tan lightly and few will not tan at all. Each one has inherited a different abili-ty to tan, but the differences do not appear until the conditions are right. An outdoor man will soon become pale if he changes to an indoor job, while a desk clerk will take on tan after a short vacation in the sun.
Sometimes people decide that being tanned is better than being pale. Sometimes they decide the opposite.
Centuries ago, most of the people in Europe were peasants and they had to work in the fields all day. Noblemen, on the other hand, did not have to work. They stayed indoors and remained pale. You could always tell a nobleman from a peasant because a peasant had a tan. As a result, a skin so pale that veins (血管) were showed was considered a mark of great beauty.
During the Industrial Revolution things changed. Farmers left their fields and went to work in factories, mines and mills. Working for long hours in dimly-lit factories and mines made their
skins pale. Wealthy people, however, could afford to travel to sunny countries. They had the leisure to lie around on the beaches and get tan. Having a tan became a sign of wealth.
In Western Europe and North America pale skin is no longer desirable. Instead of bleaching themselves white with lemon juice, many women spend their time under a sun-lamp. The desire for a quick tan has led to the invention of pills and lotions (涂剂) that darken the skin artificially without exposure to sunlight. These pills and lotions can be bought by anyone at any drugstore. A rich man can spend hundreds of dollars on a vacation in the sunny West Indies and get his suntan there. But his lowest-paid clerk can have what looks like the same tan out of a bottle for a few cents.
Besides genes, our skin color has much to do with ______.
A.exercise
B.weight
C.food
D.sunshine
第8题
Questions are based on the following passage.
(77) Heredity(遗传) is not the only thing that influences our color. Where we live and how we live after we are born are important too. For instance, our genes influence how fat or thin we are. But our weight depends mainly upon how much we eat and how much exercise we get. In the same way, our skin color depends to a large extent upon how much sunshine we get.
When summer arrives and light-colored people go to the beaches, some will tan darkly, some will tan lightly and few will not tan at all. Each one has inherited a different ability to tan, but the differences do not appear until the conditions are right. An outdoor man will soon become pale if he changes to an indoor job, while a desk clerk will take on tan after a short vacation in the sun.
Sometimes people decide that being tanned is better than being pale. Sometimes they decide the opposite.
Centuries ago, most of the people in Europe were peasants and they had to work in the fields all day. Noblemen, on the other hand, did not have to work. They stayed indoors and remained
pale. You could always tell a nobleman from a peasant because a peasant had a tan. As a result, askin so pale that the veins (血管) were showed was considered a mark of great beauty.
During the Industrial Revolution things changeD.Farmers left their fields and went to work in factories, mines and mills. Working for long hours in dimly-lit factories and mines made their
skins pale. (78) Wealthy people, however,could afford to travel to sunny countries. They had the leisure to lie around on the beaches and get tan. Having a tan became a sign of wealth. In Western Europe and North America pale skin is no longer desirable. Instead of bleaching themselves white with lemon juice, many women spend their time under a sunlamp. The desire for a quick tan has led to the invention of pills and lotions(涂剂)that darken the skin artificially without exposure to sunlight. These pills and lotions can be bought by anyone at any drugstore. A
rich man can spend hundreds of dollars on a vacation in the sunny West Indies and get his suntan there. But his lowest-paid clerk can have what looks like the same tan out of a bottle for a few cents.
Besides genes, our skin color has much to do with __________ 查看材料
A.exercise
B.weight
C.food
D.sunshine
第9题
One reason why a sheep, a less well-understood experimental subject than
the laboratory mouse, should have proved easier to clone may stem from
differences in the initial stages of the two species' embryonic development.
After reaching maturity in the ovary of the mother, the unfertilized eggs of all
(5) mammals accumulate a supply of proteins, and the means of producing fresh
protein. In this way, the mammalian egg brings with it a larder for the embryo
to make use of until its own genes activate and supply this requirement
themselves. The sheep embryo disposes of its store properly and need not
depend on its own genes until the sixteen-cell stage, four cell divisions
(10) successive to fertilization, while in contrast, the mouse embryo commences this
process more precociously, becoming reliant on the activity of its own genes
after just the first division when the fertilized egg becomes two cells.
Therefore, a foreign nucleus introduced into a sheep egg exploits a respite in its
host's biological development, allowing it to adapt to its new role before
(15) assuming genetic control.
Concomitantly, a nucleus introduced into a mouse egg must acclimatize
quickly for its genes to be able to direct embryonic development within a single
cell division, so perhaps there is insufficient time for the extensive re-
programming of compulsory gene activity. The human embryo is thought to rely
(20) on its own genes after three cellular divisions, which might or might not
provide time enough for a foreign nucleus to acclimate. However, were
scientists to comprehend the nature of the indispensable re-programming then
there is every likelihood that both mice and humans could be cloned.
Despite the long-standing availability of this technology, there has until
(25) recently been little interest in it. Some people suffering from infertility as a
result of rare hereditary diseases could produce offspring, but cloned individuals
may be at risk given scientists' limited knowledge of the long term effects of
allowing an "old" adult cell nucleus to commence life again in an egg. The
nucleus of a skin cell could have accumulated a multitude of genetic mistakes of
(30) no consequence to its role in the skin, but the same cell could prove deleterious
in other tissues, or immensely increase the probability of the affliction with
cancer. The threat to general human health posed by cloning, as opposed to the
individual, is difficult to determine, but the risks are almost certainly lower
than those encountered in the effective inbreeding of consanguine marriages,
(35) and thus there are no scientific grounds per se for banning cloning. Like other
practices inconsequential to the physical well being of humanity, but generally
deemed undesirable on moral or social grounds, the prohibition of human
cloning will ultimately rest with only a simple pragmatic decision.
In this passage, the author is primarily concerned with
A.advancing an argument against human cloning based on evidence from cloning experiments performed on lower life forms
B.measuring the technical and ethical limitations of the embryonic cloning process in mammals
C.refuting arguments against human cloning through the use of hard scientific evidence
D.illuminating the critical ethical distinctions in process between human cloning and sheep cloning
E.describing how the ethical issues in the quest for human cloning have given rise to new models of embryonic development
第10题
The donor herself may not even be aware that such a distinction exists. After years of expensive private schooling and math tutors and tennis camps and SAT prep courses and letters of recommendation from important family friends, she’s been told that, unlike beneficiaries of affirmative action, she got into an Ivy League college on pure merit.
Since it is probably safe to assume that people intent on securing high-priced Ivy League eggs are carrying some pushy-parents genes themselves, their joining forces with a donor who got into an Ivy League college by dint of her family’s willingness to fork over 10 grand to and SAT prep course could result in a child with somewhere between a dose and a half and 2 1/2 doses of pushy-parents genes. Apparently the egg seekers aren’t troubled by the prospect of having their grandchildren raised by this sort of person.
If you have any doubts about whether the dosages I cite are based on a thorough grounding in genetics and statistics and advanced microbiology, rest assured that I attended an Ivy League college myself. That was in the days, I’ll admit, when any number of people were admitted to such institutions without having shown any evidence of carrying smart-kid genes even when in trace elements. Somehow, most of these dimmer bulbs managed to graduate—every class needs a lower third in order to have an upper two-thirds—and somehow most of them are now millionaires on Wall Street.
One element many of them had going for them in the admissions process was that they were identified as “legacies”—the offspring of alumni. In Ivy League colleges, alumni children are even now admitted at twice the rate of other applicants. For that reason, egg seekers may not actually need genuine smart-kid genes for their children: after all, an applicant whose mother and father and egg donor were all alumni could be a triple legacy.
But how about the college-admission prospects of the grandchildren? As methods are perfected of enhancing a college application through increasingly expensive services—one young man mentioned in the magazine article had $25,000 worth of SAT preparation—it might become more important to have a parent who’s a Wall Street millionaire than to have smart-kid genes. Maybe it would be prudent to add a sentence to those ads in college papers: “Preference given to respondents in the lower third of the class.”
1.What does “pushy-parents” (line 9, para 1) refer to?()
A.Parents who are not smart.
B.Parents who are poor.
C.Parents who are forcefully determined to get things done.
D.Parents who are easily influenced.
2.The author tends to think that a female student from an Ivy League college is().
A.more likely to carry smart-kid genes.
B.an ideal egg donor.
C.More influenced by her parents than by anything else.
D.Not necessarily an intelligent person.
3.Which of the following is true according to the author? ()
A.Egg-seekers care nothing about the pushy-parents genes.
B.Alumni children stand a better chance to be admitted than other applicants.
C.Ivy League colleges used to admit students who showed no sign of intelligence.
D.American parents would send their children into an Ivy League college at any cost.
4.According to the passage, what may chiefly be the reason for the donor’s admission in an Ivy League college?()
A.Her own merits.
B.The affirmative action.
C.Her smart-kid genes.
D.Her parents’ efforts.
5.It could be inferred from the text that().
A.the prospects of college-admission are gloomy.
B.Ivy League colleges are increasingly expensive.
C.Wealth is more important than intelligence in application for Ivy League colleges.
D.Egg-seekers can get better genes from millionaires.
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