Does this sound like something you would be comfortable with? Why or why not?
A sound is a pressure disturbance: a sonic boom, like other explosive sounds, is the result of an abrupt change in pressure. An airplane in subsonic flight produces weak changed in pressure, but because these disturbances travel at the speed of sound, they move faster than the airplane and stay in front of it. In effect, these disturbances warn the air to get out of the way, and the an does just jet, however, gets ahead of its own pressure disturbances. Consequently a wave of suddenly com pressed air--a shock wave--builds up and is thrown off like the wave ;hat spreads from the bow of a speedboat.
Can sonic booms be eliminated? The answer is a categorical negative--they are an innerent(内在的) part of supersonic flight--but the sonic boom probably can be reduced; government and private research is now under way to improve understanding of the sonic boom. If and when the booms can be reduced to tolerable levels, commercial supersonic transports can come rata service.
Before commercial airliners travel faster than sound, problems must 0e solved regarding ______.
A.design
B.Construction
C.operation
D.all of the above
A sonic boom is like every sound in that it is ______.
A.explosive
B.caused by compressed tar
C.a pressure disturbance
D.shock wave
阅读下列短文,然后根据短文的内容从 58~61 小题的四个选择项中选出最佳的一项。
C
Have you ever argued with your loved ones over simple misunderstandings(误解)?Little wonder. We often believe we're more skillful in getting our point across than we actually are,according to Boza Keysar,a professor at the University of Chicago. In his recent study,speakers tried to express their meanings using unclear sentences. Speakers who thought listeners understood were wrong nearly half the time. Here‘s some good advice to reduce misunderstanding:
(1)Don't trust what you see from the listener. Listeners often nod,look at you or say“uhhuh”to be polite or move the conversation along. But it‘s easy to consider these as signs of understanding.
(2)Train the editor(编辑)in your head. If you say,“Beth discusses her problems with her husband,”it's not clear whether she‘s talking to her husband or about him. Try instead,“Beth talks to her husband about her problems.”or“Beth talks to others about the problems with her husband.”
(3)Ask listeners to repeat your message. Introduce your request by saying“I want to be sure I said that right.”Questions like“How does that sound?”or“Does that make sense?”may also work.
(4)Listen well. When on the receiving end,ask questions to be sure you're on the same page. After all,it isn‘t just the speaker's job to make his speech understood.
第 58 题 Why does the writer give us the advice?
A.We're not skillful enough to make clear sentences.
B.Misunderstanding is damaging our normal lives.
C.Misunderstanding occurs now and then.
D.It's impolite to say NO to others.
These photographs will show you ______.
A.what does our village look like
B.how does our village look like
C.what our village looks like
D.how our village looks like
A.What is he like
B.What does he look like
C.What does he like
D.How is he
A.Looking like a bear.
B.Taking an attitude of a bear.
C.Thinking the price would drop.
D.Making sth. as a bear.
A.What about
B.Do you like
C.What is
D.How is
[A] Principles of history and philosophy are hard to deal with.
[B] People like to see what other people do for their own model.
[C] The educated are more susceptible to errors in their daily life.
[D] That everyone does the same may not prove they are all right.
M: Do you know Lewis? W: _____? M: He is very tall and he’s got quite short, brown hair.
A.What does he look like
B.Where is he from
C.How old is he
D.How is he now
Most musicians agree that the best violins(小提琴) were made in Cremona, Italy, about 200years ago. They even sound better than violins made today. Violin makers and scientists try to makeinstruments(乐器)like the Italian violins,however,they are not the same. Why are these old Italianviolins so special? No one really knows. But many people think they have an answer.
Some people think it is the age of the violins. But there is a problem here. Not all old violins sound wonderful. Only the old violins from Cremona are special. So age cannot be the answer.
Other people think the secret to those violins is the wood. It must be from certain kinds of trees.It must not be too young or too old. Perhaps the violin makers of Cremona knew something specialabout wood for violins.
But the kind of wood may not be so important. It may be more important to cut the wood in aspecial way. Wood for a violin must be cut into the right size and shape. The smallest difference willchange the sund of the violin. Musicians sometimes think that this is the secret of the Italians.
Size and shape may not be the answer either. Scientists make new violins that are exactly the same size and shape. But the new ones still do not sound as good as the old ones. Some scientiststhink the secret may be the varnish (清漆).It makes the wood look shiny, but it also helps the soundof the instrument. Since no one knows what the Italian violin makers used in their varnish, no one canmake the same varnish today.
There may never be other violins like the violins of Cremona. And there are not many of the old violins left. So these old violins from Cremona become more and more precious. What would be the best title for the text?
A.The Secrets of Cremona Violins.
B.The History of Cremona Violins.
C.The Making of Italian Violins.
D.The Studies of Italian Violins.
What is still not clear about Cremona violins?A.The shape
B.The wood
C.The size
D.The varnish
Which of the following Words can best describe Cremona violins?A.Light
B.Shining
C.Valuable
D.Modern
请帮忙给出每个问题的正确答案和分析,谢谢!
Man:It sounds like you need to get out of the house.
Question:What does the man advise the woman to do?
A. To get a job.
B. To move to another place.
C. To visit some friends.
D. To do some outdoor exercises.