Ⅳ.阅读理解。
There’s a usual scene in movies and cartoons. A man is walking in a desert, looking for water. When up ahead, he sees a land with water. But there is no land or water at all, not even a small pool. It was just a mirage(海市蜃楼).
How does a mirage happen? The light and air play with our eyes. Normally, light travels in a straight line as a rule, but it can bend(弯曲) and change directions depending on what it passes through. This bending is called “refraction(折射)”.
If different layers(层) of air are at different temperatures, light will bend at different angles(角度) when passing through them. This can create a false image of things around.
Mirages can be seen not only over the desert, but anywhere that can take in a lot of heat, for example, on hot roads. The next time you think you see a pool of water on the road on a hot summer day, you will know it’s just a mirage—an image of the sky caused by bending light.
The mirage is the magic of nature. When you meet it next time, just take a photo and enjoy the beautiful moment.
()16.Why does the writer use the scene in Paragraph 1?
A. To share the experience in a desert.
B. To show when a mirage happens.
C. To introduce what a mirage is.

月日 星期 天气
()17.How does light travel normally?

A
B
C
()18.What does the underlined word “them” in Paragraph 3 refer to?
A. Different air layers.
B. Different angles.
C. Different temperatures.
()19.Where might we see the mirage?
A. Under a stormy sky.
B. Over a blue ocean.
C. In an icy forest.
()20.In which part of a magazine can we probably read the text?
A. Crazy Animal.
B. Modern Art.
C. Amazing Nature.

16.C 17.A 18.A 19.B 20.C