Light travels sound. [ ] A. too fast as B. much faster than C. too fast to D. much fast as 题目和参考答案——青夏教育精英家教网—

题目内容

Light travels ______ sound.

[ ]

　　A. too fast as B. much faster than

　　C. too fast to D. much fast as

答案：B

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根据句意，用括号内所给动词的适当形式填空。(必要时加助动词或情态动词)
【小题1】Mr Zhang ______(teach)us English three years ago.
【小题2】Peter turned off the computer after he finished______ (write)an e-mail.
【小题3】—Where’s Miss Wang?
一Look，she______(talk)with the students.
【小题4】Mr Liu isn’t here now．He______ (go)to Beijing.
【小题5】The children will go to the zoo if it______ (not rain)this Saturday.
【小题6】There______ (be) a meeting in our school tomorrow afternoon.
【小题7】Mr Green______(watch)TV at this time last night.
【小题8】You’d better______(eat)less food before you go to bed.
【小题9】My teacher told me that light______(travel)much faster than sound.
【小题10】English______ (speak) by many people in the world.

When the traffic lights turn red, we will stop driving a car or crossing a street. Why is red used for traffic lights instead of other colors?

As we know, scattering (散射) happens when light goes through the air. For the same media(媒质), if the wavelength is long, the scattering will be short. If the wavelength is short, then the scattering will be long.

Of all lights we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.

Using the red light can help drivers in farther areas sec the lights. It helps drivers stow down or stop in lime. If drivers don't see the red light until they are close, they may not be able to stop the car in time. An accident may happen Red can also excite people. We can act more quickly when we see the color red. In a word, red lights help drivers stop in time and help prevent accidents.

1. When the traffic lights turn ______, we will stop driving a car.

A. red B green C. yellow

2.According to the passage, the scattering of the red light is the _______.

A. longest b. weakest C. farthest

3. The underlined word "wavelength" means________ in Chinese.

A.波浪 B.光波 C.波长

4. What can the red light help drivers do?

A. It can help drivers in farther areas see the lights.

b. It can help drivers slow down or stop in time.

C. A and b

5.Which of the following is the best title?

A. Why do accidents happen

b. How does the red light travel

C. Why do we use red traffic lights

1.Listen! The radio says something bad________(happen) last night.

2.He spent as much time as he could_______(study) different subjects.

3.The teacher told us that light ___________ (travel ) much faster than sound.

4.I won’t be able to take part in the party if I ________(not be) free.

5.There ____________(not be) a lot of changes in the next 24 hours, are there?

6.They are good friends They often sit on the playground,________(talk) about their future plans.

7.Luckily, he ____________( catch) the first bus and wasn’t late for school.

8.The elderly like to keep pets _____ (make) their life better.

9.Dad said to Mike,"I hope you_________(not forget) to write to me soon.”

10.The plane ______ ( arrive). You can see your mother at once.

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