Question

【題目】 What is the sky? How high is it? What color is it? What birds can live above it? These questions are difficult to answer, aren' t they? In fact, the sky has no color. Then why does the sky look blue?

We know that there is air around the world. When planes fly, they need air to lift their wings. Planes can't fly very high. That is because the air gets thinner when they go higher. The same will happen to us if we go high enough. If we go up about 1.200 kilometers from the earth, we'll find no air there. Some birds can fly into the sky as high as a plane, but they cannot fly or live without air.

Looking up above us, you will see the blue sky with white clouds. It is usually light blue. The color would be bluer when you see on the top of a high mountain. And you will see fewer clouds in the sky between you and the sun. Sometimes the sky doesn't look blue. When the sun rises and falls, you will see red, orange, and other colors in the sky. Such are the most beautiful moments of the day.

Who can see the colors of the sky high above the earth? The astronauts! They can see those beautiful colors of the sky from the outer space. However, before flying into the outer space, they sit in a spaceship high above the earth, and there is no air at all. The sky would be that dark and its color would be black.

Now you may understand that we see colors because the air scatters（使散射） the sunlight. Light travels through the air. Without air, there would be no colors.

【1】Planes can't fly as high as possible because .

A. the sky is blue

B. the wings are heavier

C. the air becomes thinner

D. the sky has no air

【2】When you stand on the top of a high mountain， you will see .

A. more air

B. fewer clouds

C. more colors

D. redder skies

【3】In Sunning， we might see many colors in the sky at about during the day in summer.

A. 7：00 pm

B. 11： 00 pm

C. 1：00 am

D. 3： 00 am

【4】The sky changes colors because .

A. the sunlight has colors

B. the air scatters the sunlight

C. it's colorful itself

D. the world Is colorful

【5】Which is the best title（標題）?

A. Why does the sky look blue?

B. Why can't planes fly very high?

C. Why does the sky change colors?

D. Why can the astronauts see the colors of the sky?

Answer 1

【答案】

【1】C

【2】B

【3】A

【4】B

【5】C

【解析】

我們都可以看到藍天白云，事實上，天空是沒有顏色的，那為什么天空看起來是藍色的呢？這篇短文給我們介紹了這個道理，其實這是空氣散射陽光的結(jié)果，光在空氣中傳播，沒有空氣，就沒有顏色。

【1】細節(jié)理解題。根據(jù)短文第二段中Planes can't fly very high. That is because the air gets thinner when they go higher.可知，飛機不能飛得很高，那是因為當飛機飛得更高時，空氣會變稀薄。由此可知越高空氣越稀薄，故選C。

【2】細節(jié)理解題。根據(jù)短文第三段中The color would be bluer when you see on the top of a high mountain. And you will see fewer clouds in the sky between you and the sun可知，當你在一座高山上的時候，顏色會更藍，在你和太陽之間的天空中，你會看到更少的云。由此可知，站在山頂上是你會看到更少的云，故選B。

【3】推理判斷題。根據(jù)短文第三段When the sun rises and falls, you will see red, orange, and other colors in the sky. Such are the most beautiful moments of the day.可知，當太陽升起和下落的時候，你會在天空中看到紅色、橙色和其他顏色，這是一天中最美麗的時刻。結(jié)合選項可知，7點太陽升起的時候是可以看到很多顏色，故選A。

【4】細節(jié)理解題。根據(jù)短文最后一段Now you may understand that we see colors because the air scatters（使散射） the sunlight可知，我們看到顏色是因為空氣散射陽光，由此可知應(yīng)選B。

【5】主旨大意題。根據(jù)短文第一段中 In fact, the sky has no color. Then why does the sky look blue?事實上，天空沒有顏色。那為什么天空看起來是藍色的呢？可以推測，本文最好的題目是“為什么天空看起來是藍色的？”，故C選項最符合文意。