单项选择题Some animals apparently can resist cancer by strengthening their immune system in preparation for winter, Johns Hopkins researchers said on Wednesday.
The scientists said their study is the first to show that the central nervous system, reacting to environmental changes, may spark changes in the body’s immune system that control the growth of tumors.
They said if that is the ease, a better understanding of how the process works eventually could lead to new cancer treatments.
Dr. Randy Nelson, an associate professor of psychology at Hopkins, stressed at a meeting of the Society of Neuroscience that further study would be needed to confirm a connection between the length of the day, the animals’ immune system and cancer. More work also would be needed to show that the findings could be applied to human cancer.
Dr. Faye Austin, an immunologist with the National Cancer Institute in Bethesda, said: "It’s a very intriguing observation that the length of exposure to light can affect the growth of a tumour. But I think that the draws really need further work to clarify the mechanics."
But Austin said the findings were surprising and important, only because they open up a new approach for research.
Studies showed that stress weakened the immune system in animals. They figured that because winter is stressful, the season probably causes exertion (影响) on the immune system.
The researchers reasoned that animals that compensated by boosting (促进) their immune systems as winter approached would have a better chance of surviving and producing offspring.
"In the same way that animals have evolved to select the best time to breed, it struck me that animals ought to be able to predict when conditions would be challenging immunologically." Nelson said.

填空题As any woman can prove, there are some things at which her gender naturally excels. In the past decade, academic research has offered insight into the feminine advantage:
Part Ⅰ
Verbal superiority may continue from childhood to adulthood. Studies show that women excel at certain verbal-fluency tests, such as listing multiple words that begin with the same letter. Some researchers have also found that women are more adept at learning foreign languages than men are.
Part Ⅱ
According to psychologist Doreen Kimura of the University of Western Ontario, women outperform men on "precision manual tasks." In studies involving quick, accurate, small movements, and a pegboard test (in which subjects place small pegs into holes as quickly as they can), women outdo men.
Part Ⅲ
In one study of 1955, Richard L. Doty, in the University of Pennsylvania Smell and Taste Center, asked randomly selected sniffers to identify scents. He found that, on average, women outperformed men. Women also have lower odor "thresholds", meaning they can detect fainter odors than men can.
Women do better than men on hearing tests, too. And their hearing deteriorates less rapidly than men’s over time, according to Mary Anne Baker, a psychology professor at Indiana University Southeast.
Part Ⅳ
Women interrupt less, are more likely to be complimentary, and laugh at other people’s jokes more. And women even disagree agreeably, as in "That’s a good point, but —"
In numerous studies, women also read nonverbal cues—facial expressions, body movements, and changes in tone of voice—more accurately than men do, according to Hall. Women’s faces are generally more expressive than men’s, too, says Hall.
Part Ⅴ
As more women rise to upper management, researchers have examined differences in how men and women lead. Women tend to share power, encourage participation, and boost their employees’ sense of self-worth. Many of the women believe subordinates perform best when they feel good about themselves, and women tend to foster that feeling. Insignificant contrast, their male counterparts exercise more formal authority and care more about hierarchy, Rosenerfound.
Now match each of the schools to the appropriate statement.
Note: there are two extra statements.

• [A] Born to lead.
• [B] Super Senses.
• [C] Handy Women.
• [D] Social Communication.
• [E] Attentive Character.
• [F] Habit of thrift.
• [G] The Language Gap.

问答题

单项选择题Some animals apparently can resist cancer by strengthening their immune system in preparation for winter, Johns Hopkins researchers said on Wednesday.
The scientists said their study is the first to show that the central nervous system, reacting to environmental changes, may spark changes in the body’s immune system that control the growth of tumors.
They said if that is the ease, a better understanding of how the process works eventually could lead to new cancer treatments.
Dr. Randy Nelson, an associate professor of psychology at Hopkins, stressed at a meeting of the Society of Neuroscience that further study would be needed to confirm a connection between the length of the day, the animals’ immune system and cancer. More work also would be needed to show that the findings could be applied to human cancer.
Dr. Faye Austin, an immunologist with the National Cancer Institute in Bethesda, said: "It’s a very intriguing observation that the length of exposure to light can affect the growth of a tumour. But I think that the draws really need further work to clarify the mechanics."
But Austin said the findings were surprising and important, only because they open up a new approach for research.
Studies showed that stress weakened the immune system in animals. They figured that because winter is stressful, the season probably causes exertion (影响) on the immune system.
The researchers reasoned that animals that compensated by boosting (促进) their immune systems as winter approached would have a better chance of surviving and producing offspring.
"In the same way that animals have evolved to select the best time to breed, it struck me that animals ought to be able to predict when conditions would be challenging immunologically." Nelson said.

填空题As any woman can prove, there are some things at which her gender naturally excels. In the past decade, academic research has offered insight into the feminine advantage:
Part Ⅰ
Verbal superiority may continue from childhood to adulthood. Studies show that women excel at certain verbal-fluency tests, such as listing multiple words that begin with the same letter. Some researchers have also found that women are more adept at learning foreign languages than men are.
Part Ⅱ
According to psychologist Doreen Kimura of the University of Western Ontario, women outperform men on "precision manual tasks." In studies involving quick, accurate, small movements, and a pegboard test (in which subjects place small pegs into holes as quickly as they can), women outdo men.
Part Ⅲ
In one study of 1955, Richard L. Doty, in the University of Pennsylvania Smell and Taste Center, asked randomly selected sniffers to identify scents. He found that, on average, women outperformed men. Women also have lower odor "thresholds", meaning they can detect fainter odors than men can.
Women do better than men on hearing tests, too. And their hearing deteriorates less rapidly than men’s over time, according to Mary Anne Baker, a psychology professor at Indiana University Southeast.
Part Ⅳ
Women interrupt less, are more likely to be complimentary, and laugh at other people’s jokes more. And women even disagree agreeably, as in "That’s a good point, but —"
In numerous studies, women also read nonverbal cues—facial expressions, body movements, and changes in tone of voice—more accurately than men do, according to Hall. Women’s faces are generally more expressive than men’s, too, says Hall.
Part Ⅴ
As more women rise to upper management, researchers have examined differences in how men and women lead. Women tend to share power, encourage participation, and boost their employees’ sense of self-worth. Many of the women believe subordinates perform best when they feel good about themselves, and women tend to foster that feeling. Insignificant contrast, their male counterparts exercise more formal authority and care more about hierarchy, Rosenerfound.
Now match each of the schools to the appropriate statement.
Note: there are two extra statements.

• [A] Born to lead.
• [B] Super Senses.
• [C] Handy Women.
• [D] Social Communication.
• [E] Attentive Character.
• [F] Habit of thrift.
• [G] The Language Gap.

问答题

单项选择题The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference. The source of this interference remains unconfirmed, but increasingly, experts are pointing the blame at portable electronic devices such as portable computers, radio and cassette players and mobile telephones.
RTCA, an organization which advises the aviation industry, has recommended that all airlines ban such devices from being used during "critical" stages of flight, particularly take-off and landing. Some experts have gone further, calling for a total ban during all flights. Currently, rules on using these devices are left up to individual airlines. And although some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to enforce a total ban, given that many passengers want to work during flights.
The difficulty is predicting how electromagnetic fields might affect an aircraft’s computers. Experts know that portable devices emit radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they have not been able to reproduce these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not.
The fact that aircraft may be vulnerable to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As a result, loud music sound makes the passenger unable to hear the instructions turning off his radio, this is the most worrying things to airlines.

单项选择题Space is a dangerous place, not only because of meteors (流星) but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through, and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation (辐射) from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation but their spacesuits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in space. The unit of radiation is called "rem". Scientists have reason to think that a man can put up with far more radiation than 0.1 rem without being damaged; the figure of 60 rems has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage—a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed (畸形的) children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and, during the outward and return journeys, the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in space laboratory. Rugs might help to decrease the damage done by radiation, but no really effective ones have been found so far.

单项选择题

单项选择题