[填空题]In order to minimize the damages resulted from earthquakes in the future, further progress should be made in the field of ______.

[填空题]In order to minimize the damages resulted from earthquakes in the future, further progress should be made in the field of ______.

[填空题]ear

[填空题]The order from the commander was that the troops ______.(立即开拔去前线).

[简答题]In the international trade, once an order from the importer is accepted by the exporter,’ he should send a letter to the importer to confirm his acceptance of the order. If the exporter finds it difficult 10 accept the importer’s order because the goods ordered are not available or prices have changed, he should send a reply too.In this case, the exporter may recommend some substitutes, suggest other opportunities to de business together or just decline the order, but should never forget to show his regret and to give the reasons for refusal.

[单项选择]What can we learn from the Northern California Earthquake in 1989（）
A. There is still a long way to go before man can control natural disasters.
B. International cooperation can minimize the destructive force of natural disasters.
C. Technology can help reduce the damage natural disasters may cause.
D. Scientists can successfully predict earthquakes.

[单项选择]A. New order from overseas clients.
B. A mortgage.
C. A new factory.
D. Some cash to pay to supply.

[单项选择]

Sound moves from its source to the ear by wave like fluctuations in air pressure, something like the peaks and troughs or the lowest point of ocean waves. One way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound.
Using a noise maker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted--each peak is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the highest and lowest points of the noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti-sound just enough
A. composing music
B. repairing alarm systems
C. eliminating engine noises
D. intensifying fog warning sounds