Question

【題目】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 (媒質(zhì)), if the wavelength is long, the sscattering 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 places see the lights. It helps drivers slow down or stop in time. So there will be fewer accidents. Moreover, 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】According to the passage, the scattering of the red light is the _______.

A. longest B. weakest C. farthest D. brightest

【2】The underlined word “wavelength” means________ in Chinese.

A. 光波 B. 波浪 C. 波長(zhǎng) D.光波

【3】What can the red light help drivers do?

A. It can make drivers stop in time.

B. It can help drivers act more slowly.

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

D. A and C

【4】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

D. The colors of the traffic lights

Answer 1

【答案】

【1】B

【2】C

【3】D

【4】C

【解析】

試題分析：這篇短文主要介紹了在交通燈變成紅燈時(shí)我們就會(huì)停止開車和過馬路，為什么交通燈會(huì)設(shè)計(jì)成紅色而不是其他的顏色呢？文章給我們進(jìn)行了解釋。

69.【1】B細(xì)節(jié)理解題。根據(jù)第三段的第一句 ：Of all lights we can see red has the longest wavelength, so the scattering is the weakest.可知。故選B。

70.【2】C詞意猜測(cè)題。根據(jù)句意為：如果波長(zhǎng)長(zhǎng)，那么散射短。故選C

71.【3】D細(xì)節(jié)理解題。根據(jù)最后一段的第一句 ：Using the red light can help drivers in farther areas see the lights, it helps drivers stow down or stop in time. 可知，故選D

【4】C歸納理解題。根據(jù)由本文的第一段提出問題：Why is red used for traffic lights instead of other colors? 可知，故選C