Nobody can be really free from the sound. Whether we live in the middle of a modern city or a faraway village, we are surrounded

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问题     Nobody can be really free from the sound. Whether we live in the middle of a modern city or a faraway village, we are surrounded by sound every day such as the sounds from television and radio, household appliances, and traffic. Sound makes up a part of our life.
    In fact, most of us can not bear total silence. Sound gives us a sense of safety and brings us joy. Scientific tests have also proved that total silence is a very frightening experience for human beings. A recent report shows that people feel quite lonely without background sound while they are working. The background sound which doesn’t change too much may even help people to concentrate.
    However, sometimes, sound is not helpful and joyful in people’s life. Normally, we hear these sounds at safe levels that do not affect our hearing. However, when we are exposed to harmful noise—the sounds that are too loud or loud sounds that last a long time, sensitive structures in our inner ear can be damaged, causing hearing loss.
    Besides, unpleasant sounds, particularly sudden and uneven ones, may cause fear and anger. Noise is a source of stress, which can lead to tiredness, irritability and headaches. Noise can also raise blood pressure, putting strain on the heart. People living in homes exposed to high levels of road-traffic noise were more likely to report having hypertension, according to a study in Environmental Health. The researchers estimate the noise levels for the addresses of more than 24,000 Swedish. They found that people exposed to an average traffic-noise level above 64 decibels (slightly louder than a normal conversation) were 52% more likely than people exposed to 45 decibels of road noise to report having high blood pressure, a key risk factor for heart disease, after removing age, socioeconomic status, and other variables. Noise exposure could cause hypertension by persistently elevating the body’s level of stress hormones.
    Now we know that noise is harmful to our health, but can we get used to the excessive noise? The answer is NO. If, after long exposure to excessive noise, we stop hearing it — because we have become deaf!
What can be inferred from the fourth paragraph?

选项 A、Sound level above 64 decibels is unbearable by human beings.
B、Noise is a key risk factor for heart disease.
C、Noise of 45 decibels is the level of a normal conversation.
D、Hypertension is another saying of high blood pressure.

答案D

解析 由第四段第四句“People—high levels of road—traffic noise…hypertension…”可知,在道路交通噪音较大的房屋中居住的人患hypertension的可能性更大。由本段第六句“They found…above 64decibels…having high blood pressure…”可知,身处平均噪音水平64分贝(交通噪音较大)以上的人群患high blood pressure的可能性比身处道路噪音45分贝中的人群高。由此可推知,hypertension和high blood pressure意思一样。故D项正确。根据第四段第六句“They found that people exposed to an average traffic—noise level above 64 decibels(slightly louder than a normal conversation)…”可知,64分贝的音量只是比正常谈话稍微高一点,A项提到64分贝是人类难以忍受的,不符合文意;根据该句中“…having high blood pressure,a key risk factor for heart disease…”可知,高血压才是心脏病的一个主要风险因素,故B项不对;该句当中只是用64分贝和45分贝对人的影响做对比,并没有明确表示两者哪一个是正常分贝,C项过于牵强,故正确答案为D项。
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