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 accompanied 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
49 It can be inferred from the passage that ________.
A) the developing world has decided to increase its energy consumption
B) a third-world 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.
Questions 51 to 55 are based on the following passage.
Learning disabilities are very common. 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 organized.
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 learning-disabled 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. |
