流星体在快速穿过大气层时, 因磨擦而迅速加热.Moving swiftly through the atmosphere, meteoroids are heated rapidly by friction.如果流星体聚集在一起, 则每年看到的流星数都不一样.If the meteoroids are bunched together, the number of meteors seen varies from year to yea...
To record, press these two buttons together; then rewind , and then press the red button to play back.要录音就得一起按下这两个键, 而后倒回, 按下这个红键播放.To record, press these two buttons together; then rewind, and then press the red button ...