【正文】 d pressure falls, our hearts pound to pensate. As it turned out, though, our natural state is not a steady one .Researchers are finding that everything from blood pressure to brain function varies rhythmically with the cycles of sun, moon and seasons. 12 And their insights are yielding new strategies for keeping sway such mon killers as heart disease and cancer. Only one doctor in 20 has a good knowledge of the growing field of “chronotherapeutics,” the strategic use of time (chronos) in medicine. But according to a new American Medical Association poll, three out of four are eager to change that “The field is exploding, says Michael Smolensky. “Doctors used to look at us like, ?What spaceship did you guys get off ?? Now they?re thirsty to know more. In medical school, most doctors learn that people with chronic conditions should take their medicine at steady rates. “It39。s population. The average rich world resident adds about tons of CO2 yearly to the atmosphere, more than four times the level added by each Third World citizen. The US, with just seven per cent of the global population, is responsible for 22 per cent of global warming. 46.”Feedback mechanisms” in paragraph 1 most probably refer to ________. A) how plants and animals adapt to hidden factors B) how plants and animals interact with the changing climate C) how climate changes D) how climate zones shift 47. James Hansen predicts that the shift of climate zones will be acpanied by ________. A) the cutting of many trees. B) desirable environmental changes. C) successful migration of species. D) unsuccessful migration of trees. 48. We can learn from the passage that ________. A) some feedback mechanisms may slow down global warming B) the basic facts of global warming are unknown C) developing countries benefit from cheap fossil fuels D) developed countries have decided to reduce their energy consumption 8 49. It can be inferred from the passage that ________. A) the developing world has decided to increase its energy consumption B) a thirdworld citizen adds less than a ton of CO2 yearly to the atmosphere C) the world climate would soon gain its balance if we stopped greenhouse gas emissions D) future prosperity of the world is dependent on cheap fossil fuels 50. Which of the following is the main topic of the passage? A) Material progress and energy consumption. B) Prosperity and cheap fossil fuels. C) Impact of global warming on climate. D) Plants and animals in the changing climate. Passage Four Learning disabilities are very mon. They affect perhaps 10 percent of all children. Four times as many boys as girls have learning disabilities. Since about 1970, new research has helped brain scientists understand these problems better. Scientists now know there are many different kinds of learning disabilities and that they are caused by many different things. There is no longer any question that all learning disabilities result from differences in the way the brain is anized. You cannot look at a child and tell if he or she has a learning disability. There is no outward sign of the disorder. So some researchers began looking at the brain itself to learn what might be wrong. In one study, researchers examined the brain of a learningdisabled person, who had died in an accident. They found two unusual things. One involved cells in the left side of the brain, which control language. These cells normally are white. In the learning disabled person, however, these cells were gray. The researchers also found that many of the nerve cells were not in a line the way they should have been. The nerve cells were mixed together. The study was carried out under the guidance of Norman Geschwind, an early expert on learning disabilities. Doctor Geschwind proposed that learning disabilities resulted mainly from problems in the left side of the brain. He believed this side of the brain failed to develop normally. Probably, he said, nerve cells there did not connect as they should. So the brain was like an electrical device in which the wires were crossed. 9 Other researchers did not examine brain tissue. Instead, they measured the brain39。s fault. Thai is not so in other countries, where both public education and the law treat Fires as either a personal failing or a crime. Japan has many wood houses。 but, of course, it is not easy to make the_________ from one culture to another A) transaction . B) transportation C) transmission D) transition 27. We_________ that diet is related to most types of cancer but we don39。t be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can39。s large population accounts for high fire frequency 44. In what aspects should the United States learn from Japan? A) Architecture and building material. B) Education and technology. C) Laws and attitude. D) All of the above 45. To narrow the gap between the fire death rate in the United States and that in other countries, the author suggests ________. A) developing new technology B) counting more on laws and social pressure C) placing a fire extinguisher in every family D) reinforcing the safeness of household appliances Passage Three There are hidden factors which scientists call “feedback mechanisms”. No one knows quite how they will interact with the changing climate. Here39。s physical and social environment until adequate orientation and mobility skills have been established. Because observational skills are more limited, selfcontrol within the immediate surroundings is limited. The visually impaired person is less able to anticipate hazardous situations or obstacles to avoid. Orientation refers to the mental map one has of one39。re taken in the morning, the