题目内容
（请给出正确答案）
A．By letting the bus run in the morning only.
B．By limiting the number of the students.
C．By obtaining the support from the headmaster.
D．By linking the new bus service with the existing one.
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更多“A．By letting the bus run in th…”相关的问题
A.By train and by car.
B.By plane and by coach.
C.By train and by bus.
D.By bus and by plane.
A．Turning right at a red light.
B．Driving in freeways without a local driver's license.
C．Passing a school bus that is letting off. children.
D．All of the above.
W: But by the time the bus gets to my stop, there aren't any seats left.
Q: How does the woman prefer to go to work？
(14)
A．By train.
B．By bus.
C．On foot.
D．By car.
W: Thank you for your advice, but my bike was stolen last night.
Q: How would the woman most probably get to work？
(6)
A．By bus.
B．By bike.
C．By taxi.
D．On foot.
M: He ended up driving his own car. The plane was too expensive, and the bus was too slow.
Q: How did Bill go to New York？
(18)
A．By car.
B．By plane.
C．By train.
D．By bus.
听力原文： The idea of fighting a noise by making more noise sounds strange, but that's exactly what motor engineers are doing in Germany and some other countries.
Carmaker's research and development laboratories have already proved that mixing in 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 mix so that the highest point of one wave happens at the same time with 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, which not only reduces the weight of a car, but also makes the motor burn less oil and work better.
Some engineers believe that the noise-killing system will be used in most cars in 1996. 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.
(30)
A．By mixing high frequency sound waves with low frequency sound waves.
B．By producing pressure waves going in the opposite direction.
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.
A.adopting
B.adjusting
C.letting
D.making
A.hostile
B.available
C.helpless
D.subsequent
A．He is going to the hospital.
B．He is showing his hand.
C．He is letting her go.
D．He is offering help.
