C The idea of being able to walk on water has long interested humans greatly. Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid --- we simply weigh too much, and all our mass pushes down through our relatively small feet, resulting in a lot of pressure that makes us sink. However, several types of animals can walk on water. One of the most interesting is the common basilisk Basilicus basilicus, a lizard（蜥蜴）native to Central and South America. It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water’s surface with its feet. The lizard will take as many as 20 steps per second to keep moving forward. For humans to do this, we’ll need huge feet that we could bring up to our ears in order to create adequate “hitting.” But fortunately there is an alternative: cornflour. By adding enough of this common thickening agent to water (and it does take a lot), you can create a “non-Newtonian” liquid that doesn’t behave like normal water. Now if the surface of the water is hit hard enough, particles（粒子）in the water group together for a moment to make the surface hard. Move quickly enough and put enough force into each step, and you really can walk across the surface of an adequately thick liquid of cornflour. Fun though all this may sound, it’s still rather messy and better read about in theory than carried out in practice. If you must do it, then keep the water wings handy in case you start to sink --- and take a shower afterward! What is the function of the cornflour according to the passage

A:To create a thick liquid. B:To turn the water into solid. C:To help the liquid behave normally. D:To enable the water to move rapidly.

The idea that boys and girls—and men and women—are programmed by evolution to behave differently from one another is now widely acknowledged. But which of the differences between the sexes are "biological", in the sense that they have been honed by evolution, and which are "cultural" or "environmental" and might more easily be altered by changed circumstances, is still fiercely debated.
The sensitivity of the question was shown last year by an uproar at Harvard University. Larry Summers, then Harvard’s president, caused a storm when he suggested that innate ability could be an important reason why there were so few women in the top positions in mathematics, engineering and the physical sciences.
Even as a proposition for discussion, this is Unacceptable to some. But biological explanations of human behavior are making a comeback. The success of neo-Darwinism has provided an intellectual foundation for discussion about why some differences between the sexes might be innate. And new scanning techniques have enabled researchers to examine the brain’s interior while it is working, showing that male and female brains do, at one level, operate differently. The results, however, do not always support past clichés about what the differences in question actually are.
One behavioral difference that has borne a huge amount of scrutiny is in mathematics, particularly since Dr. Summers’ comments. The problem with trying to argue that the male tendency to systemize might lead to greater mathematical ability is that, in fact, girls and boys are equally good at maths prior to teenage years. Until recently, it was believed that males outperformed females in mathematics at all ages. Today, that picture has changed, and it appears that males and females of any age are equally good at computation and at understanding mathematical concepts. However, after their mid-teens, men are better at problem solving than women are.
The question raised by Dr. Summers does get to the heart of the matter. Over the past 50 years, women have made huge progress into academia and within it. Slowly, they have worked their way into the higher echelons of discipline after discipline. But some parts of the ivory tower have proved harder to occupy than others. The question remains, to what degree is the absence of women in science, mathematics and engineering caused by innate, immutable ability
Innate it may well be. That does not mean it is immutable. A variety of abilities are amenable to training in both sexes. And such training works. Biology may predispose, but it is not necessarily destiny.
We learn from Paragraph 1 that men and women______.

A:all approve of the evolution theory B:are born to behave in different ways C:recognize their differences by means of computer programs D:have more biological differences than cultural ones

Honesty is the best policy, as the English saying goes. Unfortunately, honesty often deserts us when nobody is watching, British psychologists reported last week.
Researchers at UK’s Newcastle University set up an experiment in their psychology department’s coffee room.
They set a kettle, with tea, coffee and milk on the counter and hung up a sign listing the price for drinks. People helping themselves to a cup of tea or coffee were supposed to put a few cents into a box nearby.
The scientists hung a poster above the money box and alternated each week between images of gazing eyes and pictures of flowers.
The researchers found that staff paid 2.76 times more for their drinks when the image of the eyes was hung.
"Frankly we were shocked by the size of the effect," said Gilbert Roberts, one of the researchers.
Eyes are known to be a powerful perceptual signal for humans, scientists say.
"Even though the eyes were not real, they still seemed to make people behave more honestly," said the leader of the study.
Researchers believe the effect throws light on our evolutionary past. It may arise from behavioral traits that developed when early humans formed social groups to strengthen their chances of survival. For social groups to work, individuals had to cooperate, rather than act selfishly.
"There’s an argument that if nobody is watching us, it is in our interests to behave selfishly. But when we are being watched we should behave better. So people see us as co-operative and behave the same way towards us," one scientist said.
The new finding indicates that people have striking response to eyes. That might be because eyes and faces send a strong biological signal we have evolved to respond to.
The finding can be put to practical use. For example, images of eyes could boost ticket sales on public transport and improve surveillance systems to prevent antisocial behavior.
The main idea of the passage is that

A:humans have a stronger response to eyes than to flowers. B:photos of human eyes have a positive effect on people’s behavior. C:the scientists’ new finding may have many practical uses. D:people may behave dishonestly when there’s no one aroun

Nanotechnology uses matter at the level of molecules and atoms. Researchers are finding different uses for particles with a length of one nanometer, or one-billionth of a meter. These include things like beauty products and dirt-resistant clothing. But one area where many experts believe nanotechnology holds great promise is medicine.
Last week, speakers at a program in Washington discussed using nanotechnology to improve health care in developing countries. The program took place at the Woodrow Wilson International Center for Scholars. Peter Singer at the University of Toronto says a nanotechnology called quantum dots could be used to confirm cases of malaria. He says it could offer a better way than the traditional process of looking at a person’s blood under a microscope.
In poor countries, this process is often not followed. As a result, sick people may get treated for malaria even if they do not have it. Such misuse of medicines can lead to drug resistance. Quantum dots are particles that give off light when activated. Researchers are studying ways to program them to identify diseases by lighting up in the presence of a targeted molecule.
Experts say nanotechnology shows promise not just for diagnosing diseases, but also for treating them. Piotr Grodzinski of the National Institutes of Health talked about how nanotechnology could make drugs more effective. He talked about cancer drugs already developed with nanotechnology. He says if a drug can target a cancer locally in the body, then much less of it might be needed, and that means lower side effects.
Andrew Maynard is chief scientist for the Project on Emerging Nanotechnologies at the Woodrow Wilson Center. He noted that Brazil, India, China and South Africa are currently doing nanotechnology research that could help poor countries. But he also noted that there is some risk in using nano-materials. He says nanometer-sized particles behave differently in the body and the environment compared to larger particles. Experts say more investment in research is needed to better understand these risks.
Which of the following is the possible risk in using nano-materials mentioned in the passage

A:They may cause some damage to the body cells. B:They are harmful materials themselves. C:They may store in the body. D:They may behave differently in the body and the environment.

It is time the doghow to behave properly.

A:is learning B:learns C:learned D:to learn

It is time the doghow to behave properly.

A:is learning B:learns C:learned D:to learn

It is time the doghow to behave properly.

A:is learning B:learns C:learned D:to learn