A

Light and Reflection

Light is another type of wave that carries energy. A source of light (光源) such as the sun or a light bulb gives off light rays that travel away from the light source in all directions.

A light ray is a narrow beam (光束) of light that travels in a straight line.

Most objects around you do not give off light on their own. They can be seen only if the light from another source bounces off (反彈) them and into your eyes. The process of light hitting an object and bouncing off is called reflection.

Look at the picture. The light is given off by the light bulb. Some of these light rays hit the page and are reflected (反射). The student sees the page when some of the reflected light rays enter the student’s eyes.

When a light ray hits a surface (表面) and is reflected, the reflected ray obeys the law of reflection. The angle of incidence (入射角) is always the same as the angle of reflection. This is the law of reflection. And this is true for any surface, no matter what material it is made of.

1.From the passage we know __________ is a source of light.

A. the eyes B. the moon C. the sun D. the book

2.From the passage we know that because of __________, the student can see the page.

A. the light bulb B. the book C. the light waves D. the reflected rays

3.According the last paragraph, if the angle of incidence is 35°, the angle of reflection should be _____.

A. 15° B. 35° C. 55° D. 70°

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