试题详情
阅读理解-阅读单选 较难0.4 引用1 组卷119

B vitamins(维生素)may offer some protection against the effect of air pollution,a new study suggests.

The scientists say the effect is real but stress the limitations of their work.Follow-up studies are urgently needed, they say,in heavily polluted cities like Mexico.

According to the World Health Organization (WHO),over 90% of the world's population live in heavily-polluted areas.The one of the pollutants that is considered the most dangerous is very fine particulate matter, referred to as PM2.5.At around 1/30 the width of a human hair,PM2.5 can go deep into the human lung and contribute to lung and heart health problems in the young and old.

Scientists have long suspected that PM2.5 causes what are termed epigenetic(表观遗传)changes in our cells that can damage our health.Now in this new human trial,an international team of scientists wanted to see if exposure to concentrations of PM2.5 could be mitigated by daily B vitamins.

Ten volunteers were tested initially exposed to clean air and their basic responses were measured.The same volunteers were later tested with large doses(剂量)of B vitamins while exposed to air containing high levels of PM2.5.The researchers found that a four-week B vitamin intake limited the PM2.5 effect by between 28-76% at ten gene locations.They found a similar reduction in effect on the mitochondrial DNA,the parts of cells that produce energy.

However,the researchers caution that their study,while observing a real effect,has limitations.As well as the small number of participants,there was little information on the size of the B vitamin dose that caused the response.

【小题1】What is the main idea of the text?
A.B vitamins may fight against PM2.5.
B.PM2.5 can lead to epigenetic changes.
C.Further studies should be done on PM2.5.
D.Exposure to PM2.5 is more and more serious.
【小题2】Which can replace the underlined word "mitigated" in Paragraph 4?
A.measuredB.ignored
C.reducedD.observed
【小题3】How many limitations does the text mention about the new study?
A.2.B.3.
C.4.D.5.
【小题4】How does the writer of the text like the new study?
A.He believes it deeply.B.He criticizes it strongly.
C.He thinks it needs testing again.D.He shows no opinion about it.
2017·四川内江·模拟预测
知识点:科普知识 环境污染 答案解析 【答案】很抱歉,登录后才可免费查看答案和解析!
类题推荐

Though their numbers are growing, only 27 percent of all students taking the AP Computer Science exam in the United States are female. The gender gap only grows worse from there: Just 18 percent of American computer-science college degrees go to women. This is in the United States, where many college men proudly describe themselves as “male feminists” and girls are taught they can be anything they want to be. Meanwhile, in Algeria, 41 percent of college graduates in the fields of science, technology, engineering, and math—or “stem,” are female. There, employment discrimination against women is common and women are often pressured to make amends(忍气吞声) with their abusive husbands.

So what explains the tendency for nations that have traditionally less gender equality to have more women in science and technology than their gender-progressive counterparts do? According to a new paper published in Psychological Science by the psychologists Gijsbert Stoet, at Leeds Beckett University, and David Geary, at the University of Missouri, it could have to do with the fact that women in countries with higher gender inequality are simply seeking the clearest possible path to financial freedom. And often, that path leads through stem professions.

The issue doesn’t appear to be girls’ aptitude for stem professions. In looking at test scores across 67 countries and regions, Stoet and Geary found that girls performed about as well or better than boys did on science in most countries, and in almost all countries, girls would have been capable of college-level science and math classes if they had enrolled in them.

But when it comes to their relative strengths, in almost all the countries—all except Romania and Lebanon—boys’ best subject was science, and girls’ was reading. (That is, even if an average girl was as good as an average boy at science, she was still likely to be even better at reading.) Across all countries, 24 percent of girls had science as their best subject, 25 percent of girls’ strength was math, and 51 percent excelled in reading. For boys, the percentages were 38 for science, 42 for math, and 20 for reading. And the more gender-equal the country, as measured by the World Economic Forum’s Global Gender Gap Index, the larger this gap between boys and girls in having science as their best subject.

What’s more, the countries that minted the most female college graduates in fields like science, engineering, or math were also some of the least gender-equal countries. They assume that this is because the countries that empower women also empower them, indirectly, to pick whatever career they’d enjoy most and be best at.

“Countries with the highest gender equality tend to be welfare states,” they write, “with a high level of social security.” Meanwhile, less gender-equal countries tend to also have less social support for people who, for example, find themselves unemployed. Thus, the authors suggest, girls in those countries might be more inclined to choose stem professions, since they offer a more certain financial future than, say, painting or writing.

When the study authors looked at the “overall life satisfaction” rating of each country—a measure of economic opportunity and hardship—they found that gender-equal countries had more life satisfaction. The life-satisfaction ranking explained 35 percent of the variation between gender equality and women’s participation in stem. That correlation echoes past research showing that the genders are actually more segregated by field of study in more economically developed places.

The upshot of this research is neither especially feminist nor especially sad: It’s not that gender equality discourages girls from pursuing science. It’s that it allows them not to if they’re not interested.

Then again, it could just be that, feeling financially secure and on equal footing with men, some women will always choose to follow their passions, rather than whatever labor economists recommend. And those passions don’t always lie within science.

【小题1】The function of the first paragraph is to _________.
A.explain the meaning of economic pressures.
B.lead to the main topic.
C.describe the women's status.
D.tell the condition of people's rights.
【小题2】Which of the following is True according to the psychologists Gijsbert Stoet and David Geary?
A.Stem professions are helpful to pursue financial freedom.
B.Women in countries with higher gender inequality are more independent.
C.Girls usually are born poor in stem profession.
D.Girls performed no better than boys on science in most countries.
【小题3】What does the underlined word "it" in the last but one paragraph refer to?
A.stem professionB.gender equality
C.financial secureD.overall life satisfaction
【小题4】The passage is mainly talking about _________.
A.how to balance the gender in science and technology
B.why American's democracy falls behind other countries.
C.how to choose appropriate majors for women's future.
D.why less gender equality to have more women in science and technology.

Money doesn’t grow on trees but gold does. Scientists in Western Australia claim to have made a new discovery—they have found gold in the leaves and branches of trees. The researchers believe that the trees suck up the gold from deep underground, over 30 metres down. The discovery has been described as the first of its kind in the world.

Australian gold exploration companies are pleased because it will make finding gold cheaper. Rather than drilling deep holes to find gold, they will be able to examine tree leaves and branches. The trees show what is happening under the earth’s surface. There is only a tiny amount of gold in the leaves. It would take 500 trees to make one gold ring. The gold is found using a special X-ray machine and a powerful microscope, which scan the leaves and branches.

The claim is that this is the first time that gold particles have been found in living material. However, this might not be true. Ancient Chinese wisdom understood the connection between plants and the precious stones and minerals underneath them. They used plant life to find minerals — and that was thousands of years ago. In the Zhou Dynasty, it was written in a book that a certain plant grew only near deposits (矿床) of gold. Over the next 2,000 years, Chinese people wrote about different plants and how they grew, showing where minerals and precious stones such as jade, copper, lead, silver and gold were Even more importantly, in the 1000s, Su Song described how Portulaca plants could yield mercury if crushed, dried and allowed to decay (腐烂). That was certainly the first time ever that a metal was obtained from a plant.

The Previous Secrets of the Realm of the King of Xin, written during the Ming Dynasty, described how different metals were observed and extracted (提炼) from certain plants. This knowledge was unknown in the rest of the world until about 1600, when a British man realised that oak trees grew larger and greener where there was alum in the ground. Maybe ancient Chinese knowledge has more to teach modern scientists.

【小题1】According to Australian scientists, where can gold be probably found?
A.In the roots of trees.B.In the leaves of trees.
C.In the trees everywhere.D.In the underground near trees.
【小题2】How can we tell whether there is gold or not?
A.By drilling deep holes in the trees.
B.By cutting the leaves of trees into pieces.
C.By examining the surface of the ground under the trees.
D.By scanning the leaves and branches using a special microscope.
【小题3】Who first found the link between plants and minerals?
A.Australian scientists.B.Su Song.
C.Ancient Chinese people.D.A British man.
【小题4】The author develops Paragraph 4 mainly by ________.
A.using examplesB.making comparisons
C.listing figuresD.analyzing effects

You can get a clear picture about Deep Work by Cal Newport in 5 minutes. Deep Work tells us professional activities performed in a state of distraction-free concentration that push your cognitive(认知的) capabilities to their limit. These efforts create new value and improve your skill. The ability to perform deep work is becoming increasingly rare at exactly the same time it is becoming increasingly valuable in our economy. As a consequence, the few who develop the skill, and then make it the core of their working life, will thrive(蓬勃发展).

The book tells us the core abilities for thriving in the new economy, which are the ability to quickly master hard things, the ability to produce a high level, in terms of both quality and speed. If you can’t learn, you can’t thrive. If you don’t produce, you won’t thrive—no matter how skilled or talented you are. If you haven’t mastered deep work, you’ll struggle to learn hard things. To learn hard things quickly, you must focus intensely without distraction.

The key to developing a deep work habit is to move beyond good intentions and add routines and habits to your working life designed to minimize a state of unbroken concentration. To master the art of deep work, therefore, you must take back control of your time and attention from the many entertainments on the Internet that attempt to steal them. Adopt a tool only if its positive impacts on these factors substantially outweigh its negative impacts. It’s crucial that you figure out in advance what you’re going to do with your evenings and weekends before they begin.

In the end of Deep Work, we can know that the ability to concentrate is a skill that gets valuable things done. If you’re struggling to use your mind to its fullest capacity to create things that matter, then you’ll discover, as others have before you, that depth generates a life rich with productivity and meaning.

【小题1】What is presented in the first paragraph?
A.Accurate analyses.B.Practical examples.
C.Theoretical introduction.D.Daring anticipation.
【小题2】Who will have a particular advantage in this new economy?
A.Those easy to get along well with.B.Those willing to give others a hand.
C.Those who’re very skilled or talented.D.Those who’re the best at what they do.
【小题3】Which of the following can help develop a deep work habit?
A.Quitting social media.B.Making a flexible schedule.
C.Forming a simple habit.D.Using on-demand distraction.
【小题4】What is the text?
A.A news report.B.An exam paper.
C.A book review.D.An economic article.

组卷网是一个信息分享及获取的平台,不能确保所有知识产权权属清晰,如您发现相关试题侵犯您的合法权益,请联系组卷网