From the last sentence we can learn that ______ .……
Passage 4
The controversial Anglo-French
supersonic transport plane, the Concorde, had attracted much attention because
it is unusually loud. A late-model jumbo 747, for example, creates 100 or more
decibels of sound over an eight-square-kilometer area. The Concorde spreads a
100-decibel-plus blanket of noise over some 140 square kilometers. On takeoff,
the Concorde sounds like four F-4 fighter jets taking off at once. Its
penetrating, low-frequency rumble makes the Concorde "completely distinctive"
from other jets. What bothers noise experts is that plenty of
commonplace machines are just as loud as, or even louder than, the Concorde. A
sanitation truck can be noisier, and so can a heavy diesel truck pulling away
from a stop sign. One expert who has gone out of his way to dramatize the
prevalent offensiveness of the city sound-scale is Dr. Thomas H. Fay, director
of speech and hearing at Columbia-Presbyterian Medical Center in New York. Dr.
Fay took a sound-meter into a New York City subway and proved that an
approaching train can be twice as loud as the Concorde. Since
World War Ⅱ, the number of the high-powered noise-makers, from trucks and
motorcycles to air conditioners and sirens has increased almost geometrically.
It’ s no wonder that in many areas of the country, especially in the suburbs,
the average sound level has doubled in 20 years. Noise experts estimate that
city noises are increasing a half-decibel a year. They found that in 1971 the
quietest parts of Los Angeles--thought to be a relatively quiet city--were
louder than the loudest districts of New York in
1937.
From the last sentence we can learn that ______ .
A．city noises are increasing rapidly in Los Angeles B．city noises are increasing slowly but steadily in Los Angeles C．in 1971 Los Angeles was louder than New York D．New York was very quiet in 1937
