When people are running hard, the speed can reach 24 kilometers per hour. But this speed is far from that of ostriches. The highest speed that an ostrich can run is 72 kilometers per hour. Among the two-legged animals, ostrich should be regarded as the world champion of running. Animals that run faster than ostriches belong to cheetahs. Cheetah's running speed can reach 1 10 km per hour, with an average of nearly 2000 meters per minute. Cheetah is the fastest animal on land. Perhaps, you will think that meteoroids are the fastest celestial bodies that people can see, but you are wrong. Faster than a meteoroid is around us-as long as you turn on the flashlight, a beam of light will appear immediately. The speed of light is amazing, 300 thousand kilometers per second, thousands of times faster than a meteor. If we move at the speed of light, we can make seven turns along the equator of the earth in one second. Scientists believe that the speed of light is the fastest, which is unbelievable. Who would have thought that the fastest thing in the universe could reach easily? You will see many things in the book that are extremely fast. Some you know, some you may not know. You will be surprised to find how fast they are.