题目内容
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: I hope you can understand my reasons for deciding to leave, Mrs. Harrison.
W: Do I have to remind you that we have invested a lot of time and money in your career here？
Q: What is the woman's attitude toward the man's leaving？
(12)
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Based on many studies, we can come to the conclusion that exposure to magnetic fields will
A．Paint a landscape.B．Give an oral report.C．Take a final exam.D．Buy several books.
The harm the electromagnetic radiation does to people's health is as great as or even greater than that cigarette smoking does.
Electronic Radiation Puts Your Health at Risk
Electric power systems work at around 50 Hz just above the naturally occurring frequency of 30 Hz generated by the Earth. Our bodies are tuned in to this low frequency so any frequency close to this is going to interfere with us, such as the 50 Hz AC mains power system used in the UK. ELF (Extremely Low Frequency) electromagnetic fields vibrating from 0.5 to 100 Hz, even if they are weaker than the Earth's field, interfere with the cues that keep our biological cycles properly timed.
The frequencies that ELF AC systems use are very close to the natural brain rhythms of man. The pineal gland (松果体) is the principal structure in the brain that is directly sensitive to the earth's magnetic field. As a result it functions abnormally when exposed to abnormal fields close to its own. Because the pineal gland produces a host of psychoactive chemicals, its abnormal functioning can cause neurological and behavioral problems.
Studies and Reports
The biological and medical data currently available showing the danger of ELF AC mains power frequency magnetic fields is as conclusive as the data relating to cigarette smoking and lung cancer.
The European Parliament has passed a motion for a resolution on combating the harmful effects of electromagnetic fields. Since September 1992 Sweden has officially acted on the basis that there is a connection between exposure to power frequency magnetic fields and the incidence of cancer, childhood cancer in particular.
In 1990 the United States Environmental Protection Agency stated "In conclusion, after an examination of the available data over the past 15 years, there is evidence of a positive association of exposure to magnetic fields with certain site-specific cancer, namely leukaemia, cancer of the central nervous system, and to a lesser extent, lymphomas (淋巴瘤). This is supported by many studies of children and adults across many different populations and subgroups."
What Can the Biological Effects Be？
An electromagnetic field affects growing cells, and acts as a cancer promoter. Cancer cells can increase their rate of growth significantly and develop more malignant characteristics. It also affects learning ability and behavioral and psychological mechanisms increasing the incidence of depression and suicide. Chronic exposure may lead to an increase in the incidence of brain tumors. Your brain's EEG (脑电图) rhythms change when a light switch is operated nearby. A stress response occurs which, if prolonged, can lead to an immune-system deficiency, resulting in an increased incidence of infectious diseases and cancers. Because of the effects on growing cells, young children and babies are especially at risk. Studies have shown that risks of children's cancer could increase.
What Are the Risks？
Electricity is part of our daily life. We are constantly using electrical appliances at home and at work, such as computers, photocopiers, clock radio alarms, electric blankets, microwave ovens—all with the necessary AC mains transformers and wiring. All of these produce ELF electromagnetic fields. The more power the appliance consumes the stronger the field it creates.
If you spend long periods of time close to a wiring circuit or appliance with a strong field such as a computer screen, television screen, heater, clock radio or electric blanket, you may be at risk. You may also be at risk if you live close to high voltage power lines (above or below ground) and their distribution transformers. The probable safe level for constant exposure now being discussed is 1 milligause (less for children). It would seem appropriate to exercise "prudent avoidance" and limit the exposure to you, your family and work colleagues wherever possible.
The Appliances That Make Your Brain Blow a Fuse
Brain performance can be impaired by as litt
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