单选题The pilot of the plane which flies faster than sound travels does not hear the thunderclaps because______.A the sound of plane engine travels slower than the planeB the frequency of the sound altersC the passage does not mention itD the pressure decrea

Text3 NASA has hired airplane manufacturer Lockheed Martin to build its next experimental plane,which is designed to fly faster than the speed of sound without producing the loud sonic booms that have plagued the transportation form.The plane is due to be delivered in 2021 and will cost just shy of$250 million.During a press conference hosted by the agency during which they announced the partnership,Lockheed Martin spokesperson Dave Richardson explained that the new plane will be neither a prototype for a new commercial airplane,nor a reincamation of previous supersonic jets."This is a purpose-built experimental research craft,"he said."This aircraft was designed from a clean sheet."NASA will use the plane to gather data about the impact ofits low-boom design,which the agency hopes will address the single biggest challenge of supersonic flight.Flying faster than the speed of sound produces shock waves that result in a loud booming sound."The air does not know that the airplane is coming,"Peter Coen,a NASA project manager for supersonic technology,explained during the press conference,Because no one liked hearing that noise,the Federal Aviation Administration and similar international organizations banned supersonic travel over land,Now,NASA thinks technology can break the sound barrier without being quite so loud about it.The secret is in the shape of the plane.Sonic booms form because the plane's flight produces many shock waves of different strengths headed in different directions that absorb into each other to create two strong pulses of pressure.From the testing done so far,NASA thinks the new plane's design successfully dissipates and weakens those shock waves,keeping them from forming the strong pulses responsible for booms.The plane would still produce what they've dubbed"sonic thumps,"but the hope is that those would be much easier to deal with.Once the new plane is built,NASA will run surveys on the ground to see how people respond to the sonic thumps.Then,the agency will bring that survey data to the Federal Aviation Administration and its intemational counterparts in order to revisit the rule about breaking the speed of sound over land."It's not about making a new airplane for airplanes'sake,although I love airplanes,"Richardson said."It's about the data that will be collected."If the rule change does come through,that could kick off a new era of commercial supersonic travel.33.Sonic booms result from

A.the shape ofplane.
B.the sonic thumps.
C.the strong pulses.
D.the sound barrier.

Text3 NASA has hired airplane manufacturer Lockheed Martin to build its next experimental plane,which is designed to fly faster than the speed of sound without producing the loud sonic booms that have plagued the transportation form.The plane is due to be delivered in 2021 and will cost just shy of$250 million.During a press conference hosted by the agency during which they announced the partnership,Lockheed Martin spokesperson Dave Richardson explained that the new plane will be neither a prototype for a new commercial airplane,nor a reincamation of previous supersonic jets."This is a purpose-built experimental research craft,"he said."This aircraft was designed from a clean sheet."NASA will use the plane to gather data about the impact ofits low-boom design,which the agency hopes will address the single biggest challenge of supersonic flight.Flying faster than the speed of sound produces shock waves that result in a loud booming sound."The air does not know that the airplane is coming,"Peter Coen,a NASA project manager for supersonic technology,explained during the press conference,Because no one liked hearing that noise,the Federal Aviation Administration and similar international organizations banned supersonic travel over land,Now,NASA thinks technology can break the sound barrier without being quite so loud about it.The secret is in the shape of the plane.Sonic booms form because the plane's flight produces many shock waves of different strengths headed in different directions that absorb into each other to create two strong pulses of pressure.From the testing done so far,NASA thinks the new plane's design successfully dissipates and weakens those shock waves,keeping them from forming the strong pulses responsible for booms.The plane would still produce what they've dubbed"sonic thumps,"but the hope is that those would be much easier to deal with.Once the new plane is built,NASA will run surveys on the ground to see how people respond to the sonic thumps.Then,the agency will bring that survey data to the Federal Aviation Administration and its intemational counterparts in order to revisit the rule about breaking the speed of sound over land."It's not about making a new airplane for airplanes'sake,although I love airplanes,"Richardson said."It's about the data that will be collected."If the rule change does come through,that could kick off a new era of commercial supersonic travel.35.In the eyes of the author,the new plane is

A.promising.
B.premium.
C.speedy.
D.risky.

共用题干
第二篇
The Magic of Sound
Music is one of the most beautiful forms of artistic expressions ever invented.In movies and plays, music has an added function:it not only moves people but also can shock people.
Our eardrums can withstand sound within 20 to 80 decibels（分贝）.Once sound exceeds this limit , even beautiful music will become ear-splitting noise and harm health.A strong blast（响声）of high sound can twist and break a solid iron sheet.High sound of 150 decibels can kill a healthy rat.
In movies,sometimes the hero can produce a sound that ordinary people can't hear and only those who
have the same ability can feel.In nature,there is actually sound that is beyond our hearing.In physics,the sound that exceeds 20,000Hz is called ultrasonic（超音波的）.Dolphins, whales and bats can make such high-frequency sound.It does no harm to health.
Sound less than 20Hz is called infrasonic（次声）waves.When we move, the air will vibrate.The vibration of air can produce infrasonic waves.As the frequency of infrasonic waves is close to that of people's internal organs, infrasonic wave may cause resonance（共振）in human bodies.As a result,people's vision may weaken and internal organs may rupture（断裂）.However,whether an infrasonic wave can be used as a weapon depends on its intensity.If its intensity is very low,it won't damage internal organs or a person's health.If the intensity of infrasonic wave exceeds 160 decibels,it is extremely harmful.When wind blows at a force of 3 or 4 over the sea,it will produce infrasonic waves of several decibels.Only typhoons can produce infrasonic waves of over 100 decibels.At present,scientists can only produce infrasonic weapons in the lab with the help of advanced scientific tools and powerful electric power.

What could be the best title of the passage?
A:The power of music.
B:The harms of noises.
C:The magic of sound.
D:The discovery of infrasonic waves.

Text3 NASA has hired airplane manufacturer Lockheed Martin to build its next experimental plane,which is designed to fly faster than the speed of sound without producing the loud sonic booms that have plagued the transportation form.The plane is due to be delivered in 2021 and will cost just shy of$250 million.During a press conference hosted by the agency during which they announced the partnership,Lockheed Martin spokesperson Dave Richardson explained that the new plane will be neither a prototype for a new commercial airplane,nor a reincamation of previous supersonic jets."This is a purpose-built experimental research craft,"he said."This aircraft was designed from a clean sheet."NASA will use the plane to gather data about the impact ofits low-boom design,which the agency hopes will address the single biggest challenge of supersonic flight.Flying faster than the speed of sound produces shock waves that result in a loud booming sound."The air does not know that the airplane is coming,"Peter Coen,a NASA project manager for supersonic technology,explained during the press conference,Because no one liked hearing that noise,the Federal Aviation Administration and similar international organizations banned supersonic travel over land,Now,NASA thinks technology can break the sound barrier without being quite so loud about it.The secret is in the shape of the plane.Sonic booms form because the plane's flight produces many shock waves of different strengths headed in different directions that absorb into each other to create two strong pulses of pressure.From the testing done so far,NASA thinks the new plane's design successfully dissipates and weakens those shock waves,keeping them from forming the strong pulses responsible for booms.The plane would still produce what they've dubbed"sonic thumps,"but the hope is that those would be much easier to deal with.Once the new plane is built,NASA will run surveys on the ground to see how people respond to the sonic thumps.Then,the agency will bring that survey data to the Federal Aviation Administration and its intemational counterparts in order to revisit the rule about breaking the speed of sound over land."It's not about making a new airplane for airplanes'sake,although I love airplanes,"Richardson said."It's about the data that will be collected."If the rule change does come through,that could kick off a new era of commercial supersonic travel.32.The crucial factor in the sound barrier breaking technology is

A.how to create the strong pulses of pressure.
B.how to shape the experimental plane.
C.how to run the surveys mentioned.
D.how to produce the sonic thumps.

Text3 NASA has hired airplane manufacturer Lockheed Martin to build its next experimental plane,which is designed to fly faster than the speed of sound without producing the loud sonic booms that have plagued the transportation form.The plane is due to be delivered in 2021 and will cost just shy of$250 million.During a press conference hosted by the agency during which they announced the partnership,Lockheed Martin spokesperson Dave Richardson explained that the new plane will be neither a prototype for a new commercial airplane,nor a reincamation of previous supersonic jets."This is a purpose-built experimental research craft,"he said."This aircraft was designed from a clean sheet."NASA will use the plane to gather data about the impact ofits low-boom design,which the agency hopes will address the single biggest challenge of supersonic flight.Flying faster than the speed of sound produces shock waves that result in a loud booming sound."The air does not know that the airplane is coming,"Peter Coen,a NASA project manager for supersonic technology,explained during the press conference,Because no one liked hearing that noise,the Federal Aviation Administration and similar international organizations banned supersonic travel over land,Now,NASA thinks technology can break the sound barrier without being quite so loud about it.The secret is in the shape of the plane.Sonic booms form because the plane's flight produces many shock waves of different strengths headed in different directions that absorb into each other to create two strong pulses of pressure.From the testing done so far,NASA thinks the new plane's design successfully dissipates and weakens those shock waves,keeping them from forming the strong pulses responsible for booms.The plane would still produce what they've dubbed"sonic thumps,"but the hope is that those would be much easier to deal with.Once the new plane is built,NASA will run surveys on the ground to see how people respond to the sonic thumps.Then,the agency will bring that survey data to the Federal Aviation Administration and its intemational counterparts in order to revisit the rule about breaking the speed of sound over land."It's not about making a new airplane for airplanes'sake,although I love airplanes,"Richardson said."It's about the data that will be collected."If the rule change does come through,that could kick off a new era of commercial supersonic travel.31.According to the first two paragraphs,the experimental plane

A.will need an exact budget of$250 million.
B.will be put into service in 2021.
C.is designed from an entirely new angle.
D.is based on a new commercial purpose.

共用题干
第二篇
The Magic of Sound
Music is one of the most beautiful forms of artistic expressions ever invented.In movies and plays, music has an added function:it not only moves people but also can shock people.
Our eardrums can withstand sound within 20 to 80 decibels（分贝）.Once sound exceeds this limit , even beautiful music will become ear-splitting noise and harm health.A strong blast（响声）of high sound can twist and break a solid iron sheet.High sound of 150 decibels can kill a healthy rat.
In movies,sometimes the hero can produce a sound that ordinary people can't hear and only those who
have the same ability can feel.In nature,there is actually sound that is beyond our hearing.In physics,the sound that exceeds 20,000Hz is called ultrasonic（超音波的）.Dolphins, whales and bats can make such high-frequency sound.It does no harm to health.
Sound less than 20Hz is called infrasonic（次声）waves.When we move, the air will vibrate.The vibration of air can produce infrasonic waves.As the frequency of infrasonic waves is close to that of people's internal organs, infrasonic wave may cause resonance（共振）in human bodies.As a result,people's vision may weaken and internal organs may rupture（断裂）.However,whether an infrasonic wave can be used as a weapon depends on its intensity.If its intensity is very low,it won't damage internal organs or a person's health.If the intensity of infrasonic wave exceeds 160 decibels,it is extremely harmful.When wind blows at a force of 3 or 4 over the sea,it will produce infrasonic waves of several decibels.Only typhoons can produce infrasonic waves of over 100 decibels.At present,scientists can only produce infrasonic weapons in the lab with the help of advanced scientific tools and powerful electric power.

An ultrasonic sound______.
A:is very loud
B:does harm to people's health
C:cannot be heard by people
D:is produced by the hero in movies

共用题干
第二篇
The Magic of Sound
Music is one of the most beautiful forms of artistic expressions ever invented.In movies and plays, music has an added function:it not only moves people but also can shock people.
Our eardrums can withstand sound within 20 to 80 decibels（分贝）.Once sound exceeds this limit , even beautiful music will become ear-splitting noise and harm health.A strong blast（响声）of high sound can twist and break a solid iron sheet.High sound of 150 decibels can kill a healthy rat.
In movies,sometimes the hero can produce a sound that ordinary people can't hear and only those who
have the same ability can feel.In nature,there is actually sound that is beyond our hearing.In physics,the sound that exceeds 20,000Hz is called ultrasonic（超音波的）.Dolphins, whales and bats can make such high-frequency sound.It does no harm to health.
Sound less than 20Hz is called infrasonic（次声）waves.When we move, the air will vibrate.The vibration of air can produce infrasonic waves.As the frequency of infrasonic waves is close to that of people's internal organs, infrasonic wave may cause resonance（共振）in human bodies.As a result,people's vision may weaken and internal organs may rupture（断裂）.However,whether an infrasonic wave can be used as a weapon depends on its intensity.If its intensity is very low,it won't damage internal organs or a person's health.If the intensity of infrasonic wave exceeds 160 decibels,it is extremely harmful.When wind blows at a force of 3 or 4 over the sea,it will produce infrasonic waves of several decibels.Only typhoons can produce infrasonic waves of over 100 decibels.At present,scientists can only produce infrasonic weapons in the lab with the help of advanced scientific tools and powerful electric power.

What does the author say about music?
A:It may be harmful to people's health.
B:It always cheers people up.
C:It is very often difficult to understand.
D:It sounds better when it is loud enough.