Scientists say the earth's crust began shifting 3 billion year ago.A.RightB.WrongC.Not men
Scientists say the earth's crust began shifting 3 billion year ago.
A.Right
B.Wrong
C.Not mentioned
Scientists say the earth's crust began shifting 3 billion year ago.
A.Right
B.Wrong
C.Not mentioned
Scientists say that the salt in the ocean comes from______.
A.air
B.rocks
C.the earth
D.rain
A) since
B) before
C) after
D) when
A.9%
B.19%
C.90%
D.99%
A.The small spots of light.
B.Their chemical composition.
C.Their age.
D.Their size.
A.It is good for people.
B.It actually does more harm than good.
C.It can help people keep healthy.
D.It can give them more energy.
Scientists say they've made a cool discovery about living longer.
Mice genetically engineered to have lower body temperatures live substantially longer than normal mice, researchers say in tomorrow's issue of the journal Science. The newfangled mice are only slightly cooler than standard — just 0.5 to 0.9 degrees Fahrenheit (0.3 to 0.5 degrees Celsius), an effect that occurs only during waking hours. But the temperature drop significantly increases the rodents' life spans, scientists say. Altered male mice live 12 percent longer on average, while females live 20 percent longer than regular mice.
"We've demonstrated that a modest but prolonged reduction of core body temperature can contribute to increased longevity," said lead study author Bruno Conti, a biologist and neuroscientist at the Scripps Research Institute in La Jolla, California.
Which animal did the scientists use for their experiments?
A.Mice.
B.Monkeys.
C.Dogs.
D.Pigs.
A.It hasn"t met scientists" expectation yet.
B.It hasn"t been appreciated appropriately.
C.It is secondary to what has been discovered.
D.It is what scientists have been aiming at.
听力原文: Scientists in many developing nations are studying a way to protect and control the use of forests, fishing water, grasslands and other resources. They call the system "common property". It means that people join together to abate and protect the resources. Scientists say that increased population is damaging the world resources. Too many trees are cut; grasslands and croplands are destroyed. Too many fish are taken from the fishing area. There are two traditional ways to deal with this situation. One is public: the government agency decides who may use the resources and when; or the property can be private: the owner decides how to protect the resources. Experts say these two methods often are not effective, however. They believe there is a third possibility that is neither completely governmental nor completely private. It is communal or joint control of the resources.
Scientists know that this idea of common property is not new. The system has been believed successful for a long time by groups in many countries. In South Asia, some villagers have governing systems to protect everyone's right to irrigation water. In part of Central Africa, there are traditional rules that banned the killing of some wild animals. Farmers in Syria have a system to share grasslands and fisherman in Turkey have a system to make sure no one takes too many fish. Scientists say such systems usually were developed by small groups to deal with limited problems. Rules are simple and the enforcement is based on traditional value and ways of doing things. Scientists believe such systems also would be effective in other situations. They are studying how it might produce more cooking rules for people in Indian villages. The scientific group in Costa Rice is studying common property to control land area. And a government group in Zimbabwe is studying the system to protect wild animals. Scientists do not say the common property system will solve all resource needs in developing nations, buy they believe it provides one important way to deal with the problem.
(33)
A.Property owned by a group of people.
B.Privately-owned property.
C.Government-owned property.
D.People's joint effort to share and protect natural resources.
A.To stress the mysterious nature of severe immune responses
B.To argue that anaphylaxis is mainly the result of bad luck
C.To point out that scientists disagree over what causes allergies
D.To suggest that people are crazy to eat offending substances
听力原文: Experts on dyslexia say that the problem is not a disease. They say that persons with dyslexia use information in a different way. One of the world's greatest thinkers and scientists named Albert Einstein was dyslexic. Dr Einstein said that he never thought in words the way that most of us do. He said that he thought in pictures instead. Other famous people who suffered from dyslexia include Leonardo Da Vinci, a celebrated Roman artist, Thomas Edison, a well-Known American inventor and a former American Vice president, Nelson Rockfeller.
Dyslexia was first recognized in Europe and then in the United States over 80 years ago. Many years passed before doctors discovered that people with this disorder were not mentally slow or disabled. The doctors found that the brains of dyslexia persons are rather different. In brains of most people, the left side, the part that controls language, is larger than the fight side. In the people with dyslexia, the right side of the brain is much bigger. However, research has shown that dyslexia is more common in men than in women, and it is also found more often in people who are left-handed.
(30)
A.The left-handed women.
B.The left-handed men.
C.Excellent female scientists or artists.
D.Some celebrated female presidents.