When the traffic lights turn red, we will sto...

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

九年级英语阅读理解中等难度题查看答案及解析

If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors?

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

Of all light 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 see the lights. It helps drivers slow down or stop in time. 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 light helps drivers stop in time and help prevent accidents.

1.______ has the longest wavelength of all light we can see.

A. Red               B. Green           C. Yellow          D. Black

2.Red light travels farther on ______ days.

A. windy             B. sunny           C. rainy         D. cloudy

3.Red can make people act more quickly because ____________.

A. red can make people happier              B. the scattering of red is very short

C. the scattering of red is very long           D. red can make people more excited

4.The underlined word “prevent” means ______ in Chinese.

A.逃避               B. 防止            C. 处理         D. 检查

5.The passage mainly tells us ____________.

A. why accidents happen                     B. how the red light travels

C. why we use red traffic lights               D. how to stop in time at traffic lights

九年级英语阅读理解中等难度题查看答案及解析

If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors?

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

Of all light 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 see the lights. It helps drivers slow down or stop in time. 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 light helps drivers stop in time and help prevent accidents.

1.______ has the longest wavelength of all light we can see.

A. Red　　　　 　　 　 B. Green

C. Yellow　　　　　　 D. Black

2.Red light travels farther on ______ days.

A. windy　　　　　　 B. sunny

C. rainy　　　　 　 D. cloudy

3.Red can make people act more quickly because ____________.

A. red can make people happier

B. the scattering of red is very short

C. the scattering of red is very long

D. red can make people more excited

4.The passage mainly tells us ____________.

A. why accidents happen

B. how the red light travels

C. why we use red traffic lights

D. how to stop in time at traffic lights

九年级英语阅读理解中等难度题查看答案及解析

阅读短文，从每题所给的ABC三个选项中选出最佳答案回答问题或完成句子。

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

九年级英语阅读理解中等难度题查看答案及解析

Cars and buses ___________stop when the traffic lights turn red.

A. can　 　　　　　　　　　　 B. need

C. may　 　　　　　　　　　　 D. must

九年级英语单项填空中等难度题查看答案及解析

Cars and buses ___________stop when the traffic lights turn red.

A. can　 B. need　 C. may　 D. must

九年级英语单项填空简单题查看答案及解析

Look! The traffic light has turned red. We _____ stop our car.

A.can　 　　 B.can’t　 　　 C.must 　　　 D.mustn’t

九年级英语单项填空中等难度题查看答案及解析

Look!The traffic light has turned red．We _____ stop our car．（　 ）

A．can 　　　　　　　　　 B．can’t

C．must 　　　　　　　　 D．mustn’t

九年级英语单项填空中等难度题查看答案及解析

Look! The traffic light has turned red. We _____ stop our car.

A.can　　　　　　　 　　 　　　 B.can’t

C.must　　　　　　　　 　　 D.mustn’t

九年级英语单项填空中等难度题查看答案及解析

Look! The traffic light has turned red. We _____ stop our car.

A.can　　 B.can’t　　 C.must　 D.mustn’t

九年级英语单项填空简单题查看答案及解析