SOUND: ECHO ::A.sight:rainbowB.episode:televisionC.light:reflectionD.affection:attachmentE
SOUND: ECHO ::
A.sight:rainbow
B.episode:television
C.light:reflection
D.affection:attachment
E.observation:microscope
SOUND: ECHO ::
A.sight:rainbow
B.episode:television
C.light:reflection
D.affection:attachment
E.observation:microscope
第1题
The estimate is based on the______.
A.direction of the hill
B.accepted speed of sound
C.interval between sound and echo
D.both B and C
第2题
Radar (雷达)
1. Children enjoy shouting at a high wall and hearing the sound come back to them. These sounds are called echoes (回声). Echoes have given us a number of 'valuable tools.
2. Echo sounding devices were early used in making maps of the ocean floor. Sounds or Ultrasonic (超声的) sounds make good tools for determining how deep the water is under ships. Sometimes echoes from ultrasonic distance finding devices were prevented from working by fish swimming past or by the presence of large objects. So ultrasonic devices have been replaced by other tools.
3. Radar is now a familiar tool. Like many others it was ah unexpected discovery. It was first observed by two researchers, who were studying sound communication. They were sending signals from a station on one side of a river in Washington, D .C. to a vehicle across the river. They discovered that their signals were stopped by passing ships. They recognized the importance of this discovery at once.
4. All this was of course just a start, from which our present radar has developed. The word "radar," in fact, gets its name from the term "radio detection (检测) and ranging." "Ranging" is the term for detection of the distance between an object and the radar set. Today, in our scientific age, it would be difficult to manage without radar.
5. One of the many uses of radar is as a speed control device on highways. When a person in an automobile is driving faster than the speed limit, radar will show this clearly and the traffic police can take measures to stop him.
6. A pilot cannot fly a plane by sight alone. Many conditions such as flying at night and landing in dense fog require the pilot to use radar. Human eyes are not very good at determining speeds of approaching objects, but radar can show the pi lot how fast nearby planes are moving.
A Study of Sound
B Highway Police
C Working Principles
D Early Use of "Radar"
E Useful Tools
F Discovery by Chance
Paragraph 2 ______
第3题
To get a full appreciation of what this means we must turn first to some recent human inventions. Everyoneknows that if he shouts near a wall or a mountainside, an echo will come back. The further off this solid obstacle, the longer time it will take for the return of the echo. A sound made by tapping on the main body of a ship will be reflected from the sea bottom, and by measuring the time interval between the taps andthe receipt of the echoes the depth of the sea at that point can be calculated.So was born the echo-sounding equipment, now in general use in ships. Every solid object will reflect a sound, varying according to the size and nature of the object. A shoal of fish will do this. So it is a comparatively simple step fromlocating the sea bottom to locating a shoal of fish. With experience, and with improved equipment, it is now possible not only to locate fish but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.
A few years ago it was found that certain bats emit squeaks (吱吱声) and by receiving ’he echoes they could locate and steer clear of obstacles--or locate flying insects on which they feed.This echolocation in bats is often compared with radar, the principle of which is similar.@@@@@@@ Choose correct answers to the question:
The main purpose of this passage is to ______.
A.describe that animals can make different sounds
B.prove that animals’ voices can play practical roles
C.inspire the readers to make more inventions
D.startle the readers with some shocking facts
The discovery of echolocation may help with all of the following EXCEPTA.measuring the depth of the sea
B.distinguishing different kinds of fish
C.improving the functions of radar
D.varying the size and nature of an object
By saying "A shoal of fish will do this"(Lines 6-7, Para 2), the author means ________.A.only one special kind of fish can reflect sounds
B.only one special kind of fish can be used to help locate a ship
C.a large group of fish can reflect sounds
D.a large group of fish can be used to help locate a ship
As it is discussed in the passage, the squeaks of bats can be functionally compared with ________.A.human languages
B.a mountainside
C.a shoal of fish
D.taps on a ship
Which of the following statements can be inferred from the passage?A.Animals are more intelligent than humans.
B.Humans are more intelligent than animals.
C.Animals are often compared with human inventions.
D.Humans are often inspired by animals.
请帮忙给出每个问题的正确答案和分析,谢谢!
第4题
century by the Italian naturalist Lazzaro Spallanzani.He caught some bats in a bell tower,blinded them,and released them outdoors.Four of these blind bats were recaptured after they had found their way back to the bell tower,and on examining heir stomachs‘ contents,Spallanzani found that
they had been able to capture and gorge themselves with flying insects.We know from experiments that bats easily find insects in the dark of night , even when the insects emit no sound that can be heard by human ears.A bat will catch hundreds of soft-bodied,silent-flying moths or gnats in a single hour.It will even detect and chase pebbles or cotton spitballs tossed into the air.
16.According to the author,the sonar system of bats is an example of the idea that.()
A.this is the age of technological triumphs
B.modern machines are inefficient
C.living mechanisms are often more efficient than man-made
machines
D.artificial imitations are always less efficient than living
mechanisms
17.The author suggests that the sonar system of bats ().
A.was at the height of its perfection 50 million years ago
B.is better than man-made sonar because it has had 50 million years to be refined
C.would have been discovered by man many years ago
D.is the same as it was 50 million years ago
18.The fact that“blind bats”will detect and chase cotton spitballs as well as insects is remarkable because.()
A.bats do not eat spitballs
B.cotton is harder to track
C.Spitballs make no sounds audible to human ears
D.there is purpose in the flight of insects
19.This passage was written to illustrate().
A.the deficiencies of man-made sonar
B.the dependence of man upon animals
C.that we are living in a machine age
D.that the sonar system of bats is remarkable
20.Which of the following is the main point of the passage?()
A.A bat will catch hundreds of gnats in a single hour
B.Here is a perfection in nature which sometimes cannot be matched by man‘s creative efforts
C.The phrase“blind as bat”is valid
D.director of NIH learned of the abuse
第5题
A.3 17 * * * /bin/echo“how are you?”
B.0 3 * * * /bin/echo“how are you?”
C.0 0 3 * * /bin/echo“how are you?”
D.*/3 * * * * /bin/echo“how are you?”