73. We can understand from the passage that high decibel levels of sound... A) result in bodily pain and upset the eyesight
B) can only be resisted by means of earplugs
C) are only harmful when they are continuous
D) deteriorate the nervous system permanently
74. The acoustic systems developed by SARA... A) use high-intensity sound generators and are combustion driver.
B) did not meet the requirements of the US military
C) do not, unlike other similar systems, cause any permanent damage whatsoever
D) use sound levels which range from 120 to 140 decibels
75. It s inferred in the passage that the new acoustic systems developed for the US military... A) can cause permanent damage to the eye.
B) were primarily designed for use in wartime
C) were primarily designed to break up crowds
D) sometimes produce high-intensity vibrations that cause widespread damage to buildings