题目内容
The Mystery of the Flashing Fireflies
During summer nights fireflies flash in the darkness. They look like bright spots of light dancing on the breeze. Catching them in a jar for a few minutes can be fun. Fireflies are not really flies, though. They are winged beetles. Scientists are using these special beetles to learn more about our world.
The reason a firefly flashed its light is to find a mate. There are around two thousand species, or kinds, of fireflies. Fireflies mate only with their own species. Each kind of firefly has its own flash pattern. It is important that fireflies recognize this pattern. That way they can find bugs of their own kind. The male firefly flies around in the sky while the female firefly stays close to the ground.
For many years, how a firefly flashes its light was a mystery. Scientists now know that a firefly’s light is a cold light. It gives off all of its power as light. It does not produce heat. A normal light bulb gives off only ten percent of its power as light. The rest of the power is wasted as heat. That is why a light bulb that has been on for a while is very hot. The firefly’s light does not feel hot like a light bulb.
Scientists have also learned that fireflies have a small built-in lantern. This special lantern is located inside a firefly’s body. To create light, a gas flows through tiny tubes. This causes the firefly to light up. A firefly can also turn its light on and off quickly. This puzzled scientists. They learned that short bursts of this gas make the firefly glow. When the gas fades, the light goes out. This process happens very quickly.
Scientists know that what they learn from fireflies will be important. Medical studies using fireflies are helping scientists fight illnesses in human beings. They have made new medicines from the chemicals used by fireflies to make light. Fireflies have also helped with new discoveries. New flashlights and flares have been made based on fireflies. These new flashlights and flares produce a cold light like a firefly. This way all the power makes the light shine. This little bug may be a pleasure to watch, but it is also an important part of our lives.
【小题1】Why did the author most likely include Paragraph 4?
| A．To explain how fireflies make light. | B．To describe different kinds of fireflies. |
| C．To show how much power fireflies use. | D．To describe why fireflies make light. |
| A．The Cool Light of Fireflies | B．Watching Fireflies Flash |
| C．Understanding the Patterns | D．Learning from Fireflies |
| A．shines brighter | B．does not fade | C．lasts longer | D．is not hot |
| A．Paragraph 2 | B．Paragraph 3 | C．Paragraph 4 | D．Paragraph 5 |
| A．tell why fireflies light up | B．give facts about fireflies |
| C．show how fireflies help doctors | D．compare a firefly to a light bulb |
【小题1】A【小题1】D【小题1】D【小题1】A【小题1】B
解析
