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

动词填空 (本大题共8分，每小题1分)

1._________ (make) the little baby stop crying, he tried all the ways he could think of.

2.-- What’s the noise?

--- Oh, the students ___________ (plan) their autumn trip excitedly.

3.The radio says the temperature ___________ (drop) a lot later today.

4.The Smith __________ (fly) back to New York three days ago and they will come back in two days.

5.I got up early in order __________ (not be) late for school.

6.--- Why didn’t she stop him going out?

--- Sorry, but she ___________ (write) a letter and didn’t see him go out.

7.Mr Wu told us that light __________ (travel) much faster than sound.

8.I can’t understand why such a story made him __________ (laugh) so happily.

用所给词的适当形式填空（20分）

1.She is old enough to look after __________(she).

2.Mr Black is very angry, because the students are playing ____(noise ) in the classroom.

3.He is ________(thin) of the twins.

4.The ________(40) student is a top student.

5.The ________(high) of the big man is a secret.

6.I have a good online friend __________(call) Jack.

7.You should spend as much time as you can ______(practice) English.

8.Our teacher told us that light __________(travel) faster than sound.

9.Maybe the photos of the pets are those __________(visit).

10.Rose, ______(not play) football in the street.

11.Mary looks ________(happy) today because she hasn’t passed the exam.

12.I think Olympic Games is one of ________(exciting) events in the world.

13.__________(luck) , no one lost his way in the hiking.

14.I want to go to some places of ____________(interesting) in South China.

15.What about __________(ski) with me this Sunday afternoon.

16.Why not _______(go) out for a walk after lunch?

17.She met a friend of ____(she) on her way home.

18.Mr Wang often tells us _________(not stay) out too late.

19.The boy is ___________(music). He likes singing and dancing.

20.Last week, they had a good time_________(climb) the West Hill.

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)

1.Mr Zhang ______(teach)us English three years ago.

2.Peter turned off the computer after he finished______ (write)an e-mail.

3.—Where’s Miss Wang?

一Look，she______(talk)with the students.

4.Mr Liu isn’t here now．He______ (go)to Beijing.

5.The children will go to the zoo if it______ (not rain)this Saturday.

6.There______ (be) a meeting in our school tomorrow afternoon.

7.Mr Green______(watch)TV at this time last night.

8.You’d better______(eat)less food before you go to bed.

9.My teacher told me that light______(travel)much faster than sound.

10.English______ (speak) by many people in the world.