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Because of noise outside, Nancy had great difficulty ____________ (集中注意力在实验上).
答案
更多“Because of noise outside, Nancy had great difficulty ____________ （集中注意力在实验上).”相关的问题
第1题
Does Peggy care about the noise in Woodside Road？
A．Yes, because she cannot sleep well.
B．Yes, because she cannot concentrate on her study.
C．No, because she would be out all day.
D．No, because she cannot hear it.
第2题
A．focusing
B．carrying out
C．paying for
D．continuing with
第3题
The noise killing system is not yet popular mainly because --'
[ A]it is still being tried out
[ B]drivers still have their doubts
[C] it increases the cost of car production
[ D] carmakers are not sure if it is necessary
第4题
The noise killing system is not yet popular mainly because
A．it is still being tried out
B．drivers still have their doubts
C．it increases the cost of car production
D．carmakers are not sure if it is necessary
第5题
第6题
D
To fight a noise by making more noise sounds strange, but that ' s exactly what motor engi-
neers are doing in Germany and some other countries.
Carmaker ' s research and development laboratories have already proved that mixing more noise
with the help of loudspeakers can reduce the unwanted noise. Physicists have known about the tech-
nique for a long time. Sound is made up of pressure waves in the air. If two sound waves' of the
same frequency(频率） mix so that the highest point of one wave happens at the same time as the'
lowest point of the other wave, the result is no sound. Therefore, by producing a perfect copy of
the noise and delaying it by half a wave cycle(周期) ,we can kill the unwanted noise. Using this
technique many carmakers are racing to develop noise killing systems(系统) borh inside and outside
the cars.
Another good thing about the use of noise killing systems is that it saves the need for a silencer; this not only reduces the weight of a car, but also makes the motor bum less fuel and work better. Sorpe engineers believe that the noise killing system will be used in most cars within a few
years. But the carmakers haven' t decided if they will carry it into production because it would add several hundred dollars to the cost of their cars.
69. Which of the following gives a general idea of how the noise killing system works？
[ A]By producing pressure waves going in the opposite direction.
[ B ] By mixing high frequency sound waves with .low frequency sound waves.
[C]By mixing new sound waves with the noise and sending them out together.
[D]By making copies of the unwanted sound waves and letting them out a little later.
第7题
Car makers' research and development laboratories have already proved that mixing more noise with the help of loudspeakers can reduce the unwanted noise.
Physicists have known about the technique for a long time. Sound is made up of pressure waves in the air. If two sound waves of the same frequency (频率) mix so that the highest point of one wave happens at the same time as the lowest point of the other wave, the result is no sound. Therefore, by producing a perfect copy of the noise and delaying it by half a wave cycle (周期), we can kill the unwanted noise. Using this technique many carmakers are racing to develop noise-killing systems (系统) both inside and outside the cars.
Another good thing about the use of noise-killing systems is that it saves the need for a silencer; this not only reduces the weight of a car, but also makes the motor burn less fuel and work better.
Some engineers believe that the noise-killing system will be used in most cars within a few years. But the carmakers haven't decided if they will carry it into production because it would add several hundred dollars to the cost of their cars.
Which of the following gives a general idea of how the noise-killing system works？
A．By producing pressure waves going in the opposite direction.
B．By mixing high frequency sound waves with low frequency sound waves.
C．By mixing new sound waves with the noise and sending them out together.
D．By making copies of the unwanted sound waves and letting them out a little later.
第8题
Car makers' research and development laboratories have already proved that mixing in more noise with the help of loudspeaker can reduce the unwanted noise.
Physicists have known about the technique for a long time. Sound is made up of pressure waves in tire air. If two sound waves of the same frequency mix so that the highest point of one wave happens at the same time as the lowest point of the other wave, the result is no sound. Therefore, by producing a perfect copy of the noise and delaying it by half a wave cycle, we can kill the unwanted noise. Using this technique many carmakers are racing to develop noise-killing systems both inside and outside the cars.
Another good thing about the use of noise-killing systems is that it saves the need for a silencer; this not only reduces the weight of a car, but also makes the motor burn less fuel and work better.
Some engineers believe that the noise-killing system will be used in most cars within a few years. But the carmakers haven't decided if they will put it into production because it would add several hundred dollars to the cost of their cars.
Which of the following gives a general idea of how the noise-killing system works？
A．By producing pressure waves going in the opposite direction.
B．By mixing high frequency sound waves with low frequency sound waves.
C．By mixing new sound waves with the noise and sending them out together.
D．By making copies of the unwanted sound waves and letting them out a little later.
第9题
Car makers' research and development laboratories have already proved that mixing more noise with the help of loudspeakers can reduce the unwanted noise.
Physicists have known about the technique for a long time. Sound is made up of pressure waves in the air. If two sound waves of the same frequency(频率) mix so that the highest point of one wave happens at the same time as the lowest point of the other wave, the result is no sound. Therefore ,by producing a perfect copy of the noise and delaying it by half a wave cycle(周期), we can kill the unwanted noise. Using this technique many carmakers are racing to develop noise-killing systems(系统)both inside and outside the cars.
Another good thing about the use of noise-killing systems is that it saves the need for a silencer; this not only reduces the weight of a car, but also makes the motor burn less fuel and work better.
Some engineers believe that the noise-killing system will be used in most cars within a few years. But the carmakers haven't decided if they will carry it into production because it would add several hundred dollars to the cost of their cars.
Which of the following gives a general idea of how the noise-killing system works？
A．By producing pressure waves going in the opposite direction.
B．By mixing high frequency sound waves with low frequency sound waves.
C．By mixing new sound waves with the noise and sending them out together.
D．By making copies of the unwanted sound waves and letting them out a little later.
第10题
听力原文： The tragedy of Titanic will always be remembered, because she went down on her first voyage with heavy loss of life. Titanic, the great ship, sailed for New York from' Southampton on April 10th, 1912. She was carrying 1,316 passengers and a crew of 891.
Four days after setting out, the Titanic was sailing across the icy waters of the North Atlantic. Suddenly a huge iceberg was spotted. After the alarm had been given the great ship turned sharply to avoid a direct collision. The Titanic turned just in time, narrowly missing the immense wall of ice which rose over 100 feet out of the water beside her. Suddenly, there was a slight trembling sound from below. The captain went down to see what had happened. The noise had been so weak that no one thought that the ship had been damaged. The captain realized in horror that the Titanic was sinking rapidly. He ordered to abandon ship. Hundreds of people jumped into the icy water. As there were not enough lifeboats for everybody, 1,500 lives were lost.
(30)
A．1,500.00
B．1,316.00
C．891
D．2,207.00
第11题
Then he sat down to think, "I must do something about the noise," he said.He thought and thought.At last he had an idea."Ah, I'll put some cotton in my ears.Then I won't be able to hear the noise." The next day he went to the door of his neighbor, and took hold of the bell.This time he pulled even harder.The bell rang loudly, but the thief did not hear anything.With another hard pull he got the bell out.Just then the neighbor came running out.
"Steal my bell？ I'll teach you a lesson," the angry man shouted.And he hit the thief on the nose.
The foolish thief did not know how the neighbor found out he was stealing the bell."Why did he come out just then？" he wondered.
31.The thief was trying to get his neighbor's doorbell.()
A.T
B.F
32.The thief put some cotton in his ears so as not to hear anything.()
A.T
B.F
33.The neighbor ran out probably because he knew his doorbell was being stolen.()
A.T
B.F
34.The neighbor hit the thief to punish him for stealing.()
A.T
B.F
35.The thief thought the neighbor couldn't hear the noise of the bell.()
A.T
B.F
