[填空题]Emma’s father spent much of the night with a strange woman secretly.

[填空题]Emma’s father spent much of the night with a strange woman secretly.

[填空题]My father spent 100 yuan on my present．
It ______ my father 100 yuan to buy my present．

[单项选择]—Did you enjoy the concert last night —Very much ______ wonderful concert it is!
A. What a
B. What
C. How a
D. How

[简答题]______(正是在这个用石头建成的小房子里)by his father that he spent his childhood．

[单项选择]How much is the executive suite per night？（）
A. ＄400
B. ＄40
C. ＄410
D. ＄140

[单项选择]If I had seen the film last night, I ______ much to the discussion before the class now.
A. could have contributed
B. would contribute
C. will contribute
D. would have contributed

[单项选择]

To fight a noise by making more noise sounds strange, but that’s exactly what motor engineers are doing in Germany and some other countries.
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. make a car lighter
B. make a car quieter
C. reduce the cost of a silencer
D. improve the performance of a silencer