Noise constitutes a real and present danger to people’’s health. Day and night, at home, at work, and at play, noise can produce serious 【B1】 and psychological stress. No one is 【B2】 to this stress. Though we seem to 【B3】 to noise by ignoring it, the ear, in fact, never closes and the body still 【B4】 — sometimes with extreme tension —to a strange sound in the night.
The 【B5】 we feel when faced with noise is the most common outward 【B6】 of the stress building up inside us. The more 【B7】 and more serious health hazards 【B8】 with the stress caused by noise traditionally have been given much 【B9】 attention. 【B10】 . when we are annoyed or made irritable by noise, we should consider these symptoms fair warning 【B11】 other things may be happening to us, some of which may be damaging to our health.
【B12】 many health hazards of noise, hearing loss is the most clearly 【B13】 and measurable by health professionals. The other hazards are harder to 【B14】 . For many of us, there may be a risk that 【B15】 to the stress of noise increases susceptibility to disease and infection. The more 【B16】 among us may experience noise as a 【B17】 factor in heart problems and other diseases. Noise that causes annoyance and irritability in healthy persons may have more serious consequences for those already ill in mind or body. 【B18】 . the link between noise and many disabilities or diseases has not yet been 【B19】 demonstrated, and we 【B20】 to dismiss annoyance caused by noise as a price to pay for living in the modern world.

【B9】（）

A．more
B．less
C．better
D．worse