| British cancer researchers have found
that childhood leukaemia is caused by an infection, and clusters of cases around
industrial sites are the result of population mixing that increases exposure.
The research published in the British Journal of Cancer backs up a 1988 theory
that some as-yet unidentified infection caused leukaemia—not the environmental
factors widely blamed for the disease. "Childhood leukaemia appears to be an unusual result of a common infection," said Sir Richard Doll, an internationally-known cancer expert who first linked tobacco with lung cancer in 1950. "A, virus is the most likely explanation. You would get an increased risk of it if you suddenly put a lot of people from large towns in a rural area, where you might have people who had not been exposed to the infection. "Doll was commenting on the new fi A. the cluster of leukaemia eases around the Sellafield nuclear reprocessing part B. the kind of infection that causes childhood leukaemia C. the causes of childhood leukacmia D. a new findings by British scientists [单项选择]要从学生成绩表(stu_ grade)中查询出学号(stu_ no)等于109的学生姓名(name)和成绩(grade)， (13) 可以实现这一功能。
表 stu_ grade
A. select *from stu_ grade B. select* from stu_ grade where stu_ no=’109’ C. select name, grade from stu_ grade D. select name，grade from stu_ grade where stu_ no=’109’ [填空题]Researchers say that supplements can completely take the place of real food in the near future.
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Researchers have found that migrating animals use a variety of inner compasses to help them navigate. Some (1) by the position of the Sun. Others navigate by the stars. Some use the Sun as (2) guide during the day, and then (3) to star navigation by night. One study shows that the homing pigeon uses the Earth’s magnetic fields as a guide (4) finding its way home, and there are indications that various other animals, from insects to mollusks (软体动物), can also make (5) of magnetic compasses. (6) is of course very useful for a migrating bird to be able to switch to magnetic compass when clouds cover the sun; (7) it Would just have to land and wait for the Sun to come out again. (8) with the Sun or stars to steer by, the problems of navigation are more complicated (9) they might seem at first. For example, a worker honeybee (10) has found a rich source of nectar and pollen flies rapidly home to the hive to [单项选择]
Researchers produced evidence to support what most of us already knew--that a cup of tea is the answer to any crisis. [单项选择]Researchers investigating brain size and mental ability say their work offers evidence that education protects the mind from the brain’s physical deterioration.
It is known that the brain shrinks as the body ages, but the effects on mental ability are different from person to person. Interestingly, in a study of elderly men and women, those who had more education actually had more brain shrinkage. "That may seem like bad news," said study author Dr. Edward Coffey, a professor of psychiatry and of neurology at Henry Ford Health System in Detroit. However, he explained, the finding suggests that education allows people to with stand more brain-tissue loss before their mental functioning begins to break down. The study, published in the July issue of Neurology, is the first to provide biological evidence to support a concept called the "reserve" hypothesis, according to the researchers. In recent years, investigators have developed the idea that people who are more educated A. age B. education C. health D. exercise [简答题]American and Japanese researchers are developing a smart car that will help drivers avoid accidents by predicting when they are about to make a dangerous move.
The smart car of the future will be able to tell if drivers are going to turn, change lanes, speed up, slow down or pass another car. If the driver’s intended action could lead to an accident, the car will activate a warning system or override the move. (61)"By shifting the emphasis of car safety away from design of the vehicle itself and looking more toward the driver’s behavior, the developers believe that they can start to build cars that adapt to suit people’s needs," New Scientist magazine said. Alex Pentland of the Massachusetts Institute of Technology collaborated on the project with Andrew Liu who works for the Japanese carmaker Nissan. (62) Tests of their smart car using a driving simulator have shown that it is 95 percent accurate in predicting a driver’s move 12 seconds in [单项选择]Researchers found family influenced delinquency. Attachment and involvement were both (47)______ related to delinquency. Children who were more (48)______ to and involved with their parents were less involved in delinquency. The relationship between family process factors and delinquency was (49)______ — poor parenting increased the probability of delinquent behavior and delinquent behavior further weakened the relationship between parent and child. The impact of family variables appeared to fade as adolescents became older and more (50)______ from their parents.
Additionally, researchers (51)______ the relationship between educational factors and delinquency and drug use and found that weak school commitment and poor school (52)______ were associated with increased involvement in delinquency and drug use. School success was associated with resilience. Youth who (53)______ delinquency and drug use were more attached to school and teachers and had better performance scores than y
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British cancer researchers have found that childhood leukaemia is caused by an infection and clusters of cases around industrial sites are the result of population mixing that increases exposure. The research published in the British Journal of Cancer backs up a 1988 theory that some as yet unidentified infection caused leukaemia--not the environmental factors widely blamed for the disease. 我来回答: 提交
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