题目内容
The nuclear energy is released at the Sun's center as high-energy gamma radiation, a form. of electro magnetic radiation like light as radio waves, only of every much shorter wavelength. This gamma radiation is absorbed by atoms inside the Sun, to be reemitted at slightly longer wavelengths. This radiation, in its turn, is absorbed and reemitted. As the energy filters through the layers of the solar interior, it passes through the x-ray part of the spectrum, eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape into space, without being absorbed further by solar atoms. A very small fraction of the Sun's light and heat is emitted in such directions that, after passing unhindered through interplanetary space, it hits the Earth.
What does the passage mainly discuss？
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Section A
Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer.
听力原文：M: Excuse me, Helen. Could you make copies of this and hand them out to everyone who's coming to the meeting this afternoon？
W: Certainly, but I'll just have to wait until' the copier has been fixed. It shouldn't take long.
Q: What is the relationship between the man and the woman？
(12)
A．Most people do not go to public schools.B．There is a lot of controversy over the pro
Can Drugs Make Us Happier？ Samrter？
It depends on what is meant by "happy" and "smart."
There are already drugs that brighten moods, like Prozac, and other antidepressants that control levels of a brain chemical called serotonin. While originally meant to treat depression, these drugs have been used for other psychological conditions like shyness and anxiety and even by otherwise healthy people to feel better about themselves.
But is putting people in a better mood really making them happy？ People can also drown their sorrows in alcohol or get a euphoric feeling using narcotics, but few people who do so would be called truly happy.
The President's Council on Bioethics said in a recent report that while antidepressants might make some people happier, they can also substitute for what can truly bring happiness: a sense of satisfaction with one's identity, accomplishments and relationships.
"In tike pursuit of happiness human beings have always worried about falling for the appearance of happiness and missing its reality," the council wrote. It added, "Yet a fraudulent happiness is just what the pharmacological management of our mental lives threatens to confer upon us."
Now the race is on to develop pills to make people smarter, at least in one sense. These drugs, several of them already in clinical trials, aim at memory loss that occurs in people with Alzheimer's disease or a precursor called mild cognitive impairment.
But it is lost on no one that if a memory drug works and is safe, it may one day be used by healthy people to learn faster and remember longer.
Studies have already shown that animals can be made to do both whelk the activity of certain genes is increased or decreased. Dr. Tom 'Fully, a professor at Cold Spring Harbor Laboratory, created genetically engineered fruit flies that he said had "photographic memory." In one session, he said, they could learn something that took normal flies 10 sessions.
"It immediately convinced everyone that memory was going to be just another biological process," Dr. Tully said. "There's nothing special about it. That meant that it was going to be treatable and manip-ulable."
But experts say that improving memory will not necessarily make one smarter, in the sense of I.Q. , let alone in wisdom. "It would be a mistake to think that drugs that have an impact on memory necessarily will have an effect on intelligence," said Dr. Daniel L. Schachter, chairman of psychology at Harvard.
Dr. Tully, who is also acting chief scientific officer of Helicon Therapeutics, which is developing memory pills, agreed. "You don't think better than you did before,' he said. "You just get the facts in with less practice. ' Still, he said, that would be significant help to students at exam time.
Any pill used widely by healthy people to improve memory would have to be extremely safe, so that the risks would not outweigh the benefit. Psychological side effects also remain a possibility.
"Is it a good thing to remember everything？" Dr. Tully asked. Could a brain too crammed with information suffer some sort of overload？
Dr. Joe Z. Tsien, a professor of molecular biology at Princeton who genetically engineered smarter mice a few years ago, says he is skeptical that the results can be transferred to people.
"If you look at how people improve their brain power, it's through education," he said. "That has proven to have 100 percent efficiency with minimal side effects."
There are already antidepressants that control levels of a brain chemical called serotonin.
Noise pollution is annoying, but does not result in any physical problems for people living in noisy areas.
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