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【简答题】
The Magic of Sound
Music is one of the most beautiful forms of artistic expressions ever invented. In movies and plays, music has an added function: it not only moves people but also can shock people. Is it true that an ordinary musical instrument can be so powerful
Our eardrums can withstand sound within 20 to 80 decibels. Once sound exceeds this limit, even beautiful music will become ear-splitting noise and harm health. A strong blast of high sound can twist and break a solid iron sheet. (46)
The noise from a plane’s engine is over 140 decibels. However, the sound of a flute is at most a few decibels. (47) It has been proven that people who have worked in an environment with a high sound intensity for a long time suffer varying degrees of heart disease or altered brain waves.
In movies, sometimes the hero can produce a sound that ordinary people can’t hear and only those who have the same ability can feel. In nature, there is actually sound that is beyond our hearing. In physics, the sound that exceeds 20,000 Hz is called ultrasonic. (48) It does no harm to health.
Sound less than 20 Hz is called infrasonic waves. When we move, the air will vibrate. (49) As the frequency of infrasonic waves is close to that of people’s internal organs, infrasonic wave may cause resonance in human bodies. As a result, people’s vision may weaken and internal organs may rupture. However, whether an infrasonic wave can be used as a weapon depends on its intensity. If its intensity is very low, it won’t damage internal organs or a person’s health. (50) When wind blows at a force of 3 or 4 over the sea6, it will produce infrasonic waves of several decibels. Only typhoons can produce infrasonic waves of over 100 decibels. At present, scientists can only produce infrasonic weapons in the lab with the help of advanced scientific tools and powerful electric power.
A. High sound of 150 decibels can kill a healthy rat.
B. The vibration of air can produce infrasonic waves.
C. We cannot play high-pitched music with ordinary musical instruments.
D. If the intensity of infrasonic wave exceeds 160 decibels, it is extremely harmful.
E. Dolphins, whales and bats can make such high-frequency sound.
F. Therefore, the sound of ordinary musical instruments cannot harm your health.
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【单选题】Text 2 Recent stories in the newspapers and magazines suggest that teaching and research contradict each other, that research plays too prominent a part in academic promotions, and that teaching is b...
A.
It is wrong to overestimate the importance of teaching.
B.
Teaching and research are contradictory to each other.
C.
Research can never be emphasized too much.
D.
The relationship between teaching and research should not be simplified.
【单选题】阅读下列短文，从每题所给的四个选项([A]、[B]、[C]和[D])中选出最佳选项。A I woke up very late for school that morning. I was afraid of being blamed by Mr Hamel. He had said that he would ask us about some participles...
A.
he got up late
B.
the weather was bad
C.
he didn’t like studying
D.
the weather was bright
【单选题】The Smog The SmogThe air-pollution index went up to 300 within a few days.() A. Right B. Wrong C. Not mentioned
A.
For over a month, Indonesia was in crisis. Forest fires raged out of control as the country suffered its worst drought for 50 years. Smoke from the fires mixed with sunlight and hot dry air to form a cloud of smog. This pollution quickly spread and within days it was hanging over neighboring countries including Malaysia, Singapore and Thailand.
B.
When the smoke combined with pollution from factories and cars, it soon became poisonous. Dangerous amounts of CO became trapped under the smog and pollution levels rose. People wheezed (喘息) and coughed as they left the house and their eyes watered immediately.
C.
The smog made it impossible to see across streets and whole cities disappeared as grey soot (烟灰) covered everything. In some areas, water was hosed (用胶管浇) from high-rise city buildings to try and break up the smog.
D.
Finally, heavy rains, which came in November. Put out the fires and clear the air. But the environmental costs and health problems will remain. Many people from South-Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes and factory pollution Breathing problems could well increase and many non-sufferers may have difficulties for the first time. Wildlife has suffered too. In lowland forests, elephants, deer, and tigers have been driven out of their homes by smog.
E.
But smog is not just an Asian problem. In fact .was world was first used in London in 1905 to describe the mixture of smoke and thick fog. Fog often hung over the capital. Sometimes the smog was so thick and poisonous that people were killed by breathing problems or in accidents.
F.
About 4,000 Londoners died within five days as a result of thick smog in 1952.
【单选题】To keep the wheels of industry, we manufacture consumer goods in endless quantities, and, in the process, are rapidly exhausting our resources. But this is only half the problem. What do we do with ma...
A.
Population explosion.
B.
Too much consumption.
C.
It is out-dated to reuse things.
D.
High unemployment rate.