《2025年高效精练九年级英语上册译林版》

五、阅读理解。
Many of us have seen rainbows in the sky once the Sun starts shining again after it rains. For us to see a rainbow, the conditions need to be just right. We need some water drops in the air, like rain or even fog, and we need the Sun to be behind us and quite low to the ground. This is because a rainbow is created by light passing through water drops.
The light that comes from the Sun seems white to us. But the white light we see is made up of a mix of different colours. When the light goes through a raindrop, these colours can separate out.
Each of the colours in the rainbow has a different "wavelength(波长)". Raindrops look like little balls. When light hits one of these little balls of water, the light can change direction. We call this "refraction(折射)". Each of the different wavelengths is refracted differently. If the light hits the raindrop at the right place, the refraction separates the wavelengths out into their different colours.
We are taught there are seven colours: red, orange, yellow, green, blue, indigo and violet. But this isn't exactly true. Blue and green are next to each other in the rainbow, which is why we can see turquoise(a mix of blue and green). Brown is a mix of red and green. But they aren't next to each other in the rainbow, so we don't see them mix to make brown.
We would never see black and white in a rainbow. Black is what we see when there's no light at all. On the other hand, white is a mix of all the colours together. When light is refracted by raindrops, it separates the white light out, meaning it is no longer white.
( )1. We can see a rainbow under the right conditions because ______.
A. the raindrops are like little balls B. the light goes through raindrops
C. the sunshine seems to be colourful D. the weather is foggy after it rains
( )2. According to the passage, what can we know about the colours in the rainbow?
A. They can become brown or black. B. There are only seven colours in all.
C. They mix to make the white light. D. Their own places can be changed.
( )3. Which part of a magazine may this passage be taken from?
A. Science. B. Health. C. Culture. D. Fashion.

答案： 1. B 2. C 3. A