A beam of light will not bend round corners unless to do so with the help of a reflecting device . A.having been made B.being made C.made D. you make 题目和参考答案——青夏教育精英家教网—

题目内容

A beam of light will not bend round corners unless______to do so with the help of a reflecting device . A.having been made B.being made C.made D. you make

解析:

unless引起条件状语从句中后面省略了it was。

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　　Some radio signals are reflected when they meet solid objects; for example, television signals are reflected when they meet walls and houses, or when they meet an aircraft in the sky. The picture is not clear when the signals are reflected like this. When a plane is flying near the house, the picture on the television screen sometimes dances about in a very troublesome (讨厌的) way.

　　These reflections, which led Watt to the science of radar, are now used a great deal. Radar instruments (仪器) can show the direction and the distance of aircraft. The signals are reflected only when the instrument points at the aircraft; this shows the direction. How do we find the distance?

　　Electromagnetic (电磁的) waves travel at a speed of 186, 300 miles per second. We know when the signal is sent out; we notice when it comes back. The signal takes a small fraction (小部分) of a second to go and return, but this time is known. So we know the distance from the ground to the plane.

　　Radar is very important to ships on the sea. In most big ships, a radar instrument is always watching the sea on all sides. It transmits (发射) a beam [(光线的)束] of radar waves and turns round all the time. If any other ship reflects the signal, a white spot is shown on a screen on board.

　　Big aircraft also use radar. The instrument finds other aircraft in the sky. A man’s eye is not good enough to do this because it cannot see far enough, but the radar beam can see for many miles.

　　A big plane flies at about 600 miles per hour, which is ten miles per minute. If two jet planes are flying towards each other, they are twenty miles nearer together after a minute has passed. This is dangerous unless the pilots know the facts and the radar instruments show them the facts.

1．What is necessary for the reflection of a radio signal is the ________ of an object.

[　　]

2．It can be inferred that Watt got the idea of his invention of radar from ________.

[　　]

A．the science of radar

B．shooting stars

C．the reflection of a radio signal

D．none of these

3．By the use of radar we can know ________.

[　　]

A．the distance of a solid object far away

B．everything we want to see

C．the direction of a far-away object

D．Both A and C.

4．The speed of electromagnetic waves is ________.

[　　]

A．600 miles per second

B．more than 180 thousand miles per second

C．about 18 thousand miles per second

D．none of the above

5．When a radar instrumant spots something, we can see, according to the author, ________ on its screen.

[　　]

A．some electromagnetic waves

B．a beam of light

C．a white spot

D．some numbers

阅读下列应用文及相关信息，并按要求匹配信息，在答题卡上将对应题号的相应选项字母涂黑。

首先，请阅读以下网页信息。

A. Shaolin Kungfu

Shaolin Kungfu is one of the most influential genres of Chinese martial arts, and it’s named after where it originated—the Shaolin Temple, founded on the Songshan Mountain in Dengfeng County, Henan Province in Central China. The monks in the Shaolin Temple began to study martial arts during the Northern and Southern dynasties and this tradition prevailed during the Sui and Tang dynasties.

B. Kunqu Opera

Kunqu Opera is one of the oldest forms of opera still existing in China, with its origins dating

back to the end of the Yuan dynasty. It has distinguished itself by the virtuosity of its rhythmic patterns and has exerted a dominant influence on all the more recent forms of opera in China, including the Sichuan and Beijing operas. In 2001, UNESCO proclaimed Kunqu Opera as a masterpiece of the Oral and Intangible Heritage of Humanity.

C. Puppet Shows

Chinese puppetry has a long history. It is noted for its many types of puppets and superb manipulative skills. It’s a truly unique art combining opera, music, fine art and craftsmanship. It creates magic with a beam of light. Puppet shows from various places have their own unique characteristics with strong local color in terms of figure modeling.

D. T’ai Chi Ch’uan

T’ai Chi Ch’uan is a major division of Chinese martial arts. Literally, T’ai Chi Ch’uan means “supreme ultimate fist”; T’ai means “supreme”, Chi means “ultimate”, and Ch’uan means “fist”. T’ai Chi Ch’uan has its philosophical roots in Taoism and is considered an internal martial art, utilizing internal energy, or Qi, and following the simple principle of “subduing the vigorous by the soft.”

E. Traditional Chinese Medicine

In Chinese medicine, doctors use various diagnostic methods to get full and detailed information about the patients and to guide their treatment. The methods include observation, auscultation and olfaction, interrogation, and checking the pulse and heart rate. They are also known as the four major methods, each having a distinctive function.

F. Xianzi Dance

The Xianzi dance, also called Xie or Ye, is danced to the accompaniment of a Tibetan-style

two-string instrument. The most typical kind of Xianzi Dance is Batang Xianzi in Ganzi, Sichuan Province . Batang is a Tibetan inhabited area. The dancers dance in a circle or randomly, sometimes resembling a winding dragon. They sing to each other to express their feelings.

以下是相关人物信息，请将相关人物信息与适合他们的网页信息匹配起来。

1.Janet, who likes Chinese traditional art very much, is a dancing teacher in California University. She wants to know more about a truly unique art combining opera, music, fine art and craftsmanship.

2.Cathy is a medical college student in UK. Now she is preparing her thesis about other countries’ medicine, so she wants to find some information online.

3.Kate is a college student in America. She wants to get more information about Chinese traditional art, especially Chinese traditional music.

4. Jason, who has been living in America for about 30 years, wants to learn some Chinese Kungfu which is represented by the famous symbol of Yin and Yang.

5.Freda, a 23-year-old girl, is fond of playing Tibetan-style instrument. This time she decides to visit Sichuan and plans to know more about its typical dance.

It can be seen that droplets and ice crystals behave somewhat like dust in the air in a beam of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about

without fixed direction. But in fact dust particles（分子） are much larger than water droplets and they finally fall. The average size of a cloud droplet is only 0.0004 inch in diameter（直径）. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it doesn't fall out of moving air at all. Only when the droplet grows to a diameter of 0.008 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size larger enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called "coalescence".

1. Ice crystals do NOT immediately fall to Earth because .

A. they are kept up by air currents

B. most of them change into steam

C. they combine with other chemicals in the atmosphere

D. their electrical charges draw them away from the earth

2. The underlined word "random" in line 10 most probably means .

A. unpredictable B. strict C. independent D. abnormal

3. What can be inferred about drops of water larger than 0.008 inch in diameter?

A. They never occur.

B. They are not affected by the force of gravity.

C. In moving air they would fall to earth.

D.In still air they fall a speed of thirty-two miles per hour.

4. How much bigger is the rain drop than a loud droplet?

A. 200 times bigger

B. 1,000 times bigger

C. 100,000 times bigger

D. 1,000,000 times bigger

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth's gravity pulls it. But every cloud is made of water droplets or ice crystal(冰晶). Why doesn't rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are extremely small. The effect of gravity on them is slight. Air currents move and lift droplets so that the net downward amount of water is zero, even though the droplets are moving constantly.
It can be seen that droplets and ice crystals behave somewhat like dust in the air in a beam of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about
without fixed direction. But in fact dust particles（分子） are much larger than water droplets and they finally fall. The average size of a cloud droplet is only 0.0004 inch in diameter（直径）. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it doesn't fall out of moving air at all. Only when the droplet grows to a diameter of 0.008 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size larger enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called "coalescence".
【小题1】 Ice crystals do NOT immediately fall to Earth because .