题目内容

B

American researchers found females are the more talkative sex because of a special “language protein” in the brain.

The study, conducted by neuroscientists(神经学家) and psychologist from the University of Maryland, concluded that women talked more because they had more of the Foxp2 protein. The research, published in the Journal of Neuroscience, found that higher levels were found among humans that were women but in rats that were males. Their findings came after it was previously claimed that ladies speak about 20,000 words a day – over 13,000 more than men. “This study is one of the first to report a sex difference in the expression of a language-associated protein in humans or animals,” said Prof Margaret McCarthy, who led the study. In their study, the researchers attempted to determine what might make male rats more vocal than their female friends.

They separated four-day-old rats from their mothers and then counted the number of times they cried out in the “ultrasonic(超声波的) range”, the frequencies higher than humans can hear, over five minutes. While both sexes called out hundreds of cries, the males called out twice as often, they found. But when the pups were returned to their mother’s cage, she fussed over her sons first. Tests conducted on the parts of the brain known to be associated with vocal calls showed the male pups have up to twice as much Foxp2 protein as the females. The researchers then increased the production in the brains of female pups and reduced it in males. This led to the female rats crying out more often and their mothers showing more interest to them. In contrast, males became less “talkative”.

The researchers then tested samples from ten children, aged between three and five, which showed that females had up to 30 per cent more of the Foxp2 protein than males, in a brain area key to language in humans.

“Based on our observations, we assume higher levels of Foxp2 in girls and higher levels of Foxp2 in male rats is an indication that Foxp2 protein levels are associated with the more communicative sex,” said Prof McCarthy.

“Our results imply Foxp2 as a component (成分)of the neurobiological basis of sex differences in vocal communication in mammals.”

1.From the second paragraph, we can learn that ________.

A. women always speak more words than men

B. men and male rats have low levels of language protein

C. women and male rats have similar levels of Foxp2

D. McCarthy isn’t the first to find females more talkative

2.The underlined phrase “fussed over” in the third paragraph probably means______.

A. paid attention to B. related to

C. put pressure on D. counted on

3.The researchers carried out the experiments on rats in order to _______.

A. test which part of the brain is key to language in rats and humans

B. prove the levels of Foxp2 protein in humans and rats are different

C. determine the reason why female rats are more talkative than male rats

D. discover the association between Foxp2 protein and vocal communication

4.Which of the following can be the best title for the passage?

A. Tests on humans and rats

B. Why women are the talkative sex

C. Sex differences in Foxp2 protein

D. Foxp2 protein determines oral ability

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It’s never a real problem for us when the weather gets cold. We can put on more clothes, stay next to a fireplace, turn on the air conditioner or simply travel to a warmer city to spend the winter – people have many different ways of dealing with the cold.

But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat ( 发热) to keep themselves warm. So how do they manage to survive the freezing winter?

It turns out that plants have their own strategies (策略) too, said a study published on Dec 22 in the journal Nature.

According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues (活组织) can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite ( 相当于冻疮),” Zanne told Science Daily. Also, the process of freezing and thawing (解冻) can cause air bubbles (气泡) to form in the plant’s water transport system. “If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant,” she explained.

To live through cold weather, plants have developed three traits (特性) , according to the study. Some plants, such as oak trees(橡树), avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves – and growing new leaves and water transport cells when the warm spring returns.

Other plants, pine trees(松树) for example, protect themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.

The third strategy is also the most extreme – some plants die on the ground in winter and start growing as new plants from seeds when conditions get warmer.

However, the study also found that these smart strategies were developed very slowly – over millions

of years of evolution ( 进化). This leads scientists to worry that plants may not be able to deal with human-caused climate change, which has only started occurring over the past few decades.

Scientists are hoping that this study can help people find possible ways to save plants from the threat

of climate change.

1.What is the article mainly about?

A. Why plants are not afraid of the winter chill.

B. The ways that plants survive cold weather.

C. Changes in plants’ water transport system in winter.

D. How plants evolve to keep up with climate change.

2.According to the article, if a plant freezes in the winter, ______.

A. it produces more living tissues to stay alive

B. its leaves quickly fall out and its roots begin to die

C. lots of air bubbles form in its water transport system

D. its water transport system could be blocked in the spring

3.What are scientists worried about when it comes to plants according to the article?

A. Plants may not be able to adapt to the increasingly cold climate.

B. Human activities might have a great impact on the pace of plants’ evolution.

C. Plants may not be able to evolve fast enough to adapt to human-caused climate change.

D. The strategies plants develop are not good enough to protect them against cold.

E

However wealthy we may be, we can never find enough hours in the day to do everything we want. Economics deals with this problem through the concept of opportunity cost, which simply refers to whether someone’s time or money could be better spent on something else.

Every hour of our time has a value. For every hour we work at one job we could quite easily be doing another, or be sleeping or watching a film. Each of these options has a different opportunity cost—namely, what they cost us in missed opportunities.

Say you intend to watch a football match but the tickets are expensive and it will take you a couple of hours to get to and from the stadium. Why not, you might reason, watch the game from home and use the leftover money and time to have dinner with friends? This—the alternative use of your cash and time—is the opportunity cost.

For economists, every decision is made by knowledge of what one must forgo—in terms of money and enjoyment—in order to take it up. By knowing precisely what you are receiving and what you are missing out on, you ought to be able to make better-informed, more reasonable decisions. Consider that most famous economic rule of all: there’s no such thing as a free lunch. Even if someone offers to take you out to lunch for free, the time you will spend in the restaurant still costs you something in terms of forgone opportunities.

Some people find the idea of opportunity cost extremely discouraging: imagine spending your entire life calculating whether your time would be better spent elsewhere doing something more profitable or enjoyable. Yet, in a sense it’s human nature to do precisely that we assess the advantages and disadvantages of decisions all the time.

In the business world, a popular phrase is “value for money.” People want their cash to go as far as possible. However, another is fast obtaining an advantage: “value for time.” The biggest restriction on our resources is the number of hours we can devote to something, so we look to maximize the return we get on our investment of time. By reading this passage you are giving over a bit of your time which could be spent doing other activities, such as sleeping and eating. In return, however, this passage will help you to think like an economist, closely considering the opportunity cost of each of your decisions.

1.According to the passage, the concept of “opportunity cost” is applied to ________.

A. weighing the choice of opportunities

B. reducing missed opportunities

C. making more money

D. taking more opportunities

2.The “leftover ... time” in Paragraph 3 probably refers to the time ________.

A. taken to have dinner with friends

B. spared for watching the match at home

C. saved from not going to watch the match

D. spent on the way to and from the match

3.What are forgone opportunities?

A. Opportunities you make up for.

B. Opportunities you forget in decision-making.

C. Opportunities you give up for better ones.

D. Opportunities you miss accidentally.

4.What is the author’s attitude towards the concept of “opportunity cost”?

A. Indifferent B. Negative

C. Subjective D. Objective

Teamwork is all about working together to achieve a common goal or purpose. Is teamwork out of date? Why is it so hard to effectively conduct teamwork in those things?

One way we employ teamwork in everyday lives is by becoming a parent. It is a parent's job to teach their children and the basic skills and give them the knowledge they need to be successful in life. For example, the mother teaches her children manners and good health skills, while the father teaches them how to catch a ball or drive a car. However, in today's society, we find that more and more parents are experiencing that the teamwork is a one-sided thing. According to a report, there are 13.7 million single parents raising their children in the US and this could be due to the fact that parents don't take responsibility for their children, so they leave one parent to do it alone. This is a sad fact, but it reflects that effective teamwork is losing ground in the parenting aspect of our everyday lives.

Another place where teamwork affects us greatly is in our jobs. It doesn't matter if you are a small or large company; if you have at least one employee and yourself, then teamwork will be present. I have noticed that with the current economic recession(衰退期), people are racing to grab jobs but the quality of people's work has gone down greatly. It just appears to me that people do not take pride in their work any more. They want to get to work as fast as they can, just to receive the paycheck, but their quality standards fly right out the window. So I think teamwork is losing its ground in the workforce. There are too many people who want to work independently and forget they are a part of a team.

As you can see, we run into the aspects of teamwork in just about everything we do. Do you believe teamwork is really losing ground in today's society? I think it is.

1.Why does teamwork disappear in the parenting aspect of our daily life?

A. Parents have no time to spare with their children.

B. Parents have no chances to teach their children about it.

C. Many children are often brought up by a single parent.

D. Many children are independent to deal with their matters.

2.Teamwork is losing ground in workforce mainly because -

A. workers don't like to work together with others

B. workers' sense is affected by economic recession

C. workers want to prove they are more capable

D. fewer workers are employed to save money

3.The author wants us to believe his opinion by_ _.

A. listing some data

B. giving some examples

C. asking some questions

D. analyzing some cases

4.The underlined phrase "fly right out the window" in Paragraph 3 means_______ .

A. disappear B. improve

C. increase D. matter

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