国产热热热精品,亚洲视频久久】日韩,三级婷婷在线久久,99人妻精品视频,精品九热人人肉肉在线,AV东京热一区二区,91po在线视频观看,久久激情宗合,青青草黄色手机视频

您現(xiàn)在的位置: > Language Tips > Easy English > Odd Question  
 





  What would happen if there were no dust?
[ 2006-03-23 11:45 ]

Most of us who have ever cleaned a house would be much happier if there were less dust.

However, without dust there would be less rainfall and sunsets would be less beautiful.

Rain is formed when water molecules in the air collect around particles of dust. When the collected water becomes heavy enough the water droplet falls to the earth as rain. Thus water vapor could be much less likely to turn to rain without the dust particles.

The water vapor and dust particles also serve to reflect the rays of the sun. At sunrise and sunset, when the sun is below the horizon, the dust and water vapor molecules reflect the longer, red, wavelengths of light such that we can see them for more time (starting earlier in the case of sunrise and lasting longer in the case of sunset) than any of the other wavelengths. The more dust particles in the air the more colorful the sunrise or sunset.

 

 
 
 




淄博市| 涿鹿县| 祁东县| 贺州市| 大足县| 安乡县| 上饶市| 寿阳县| 嘉义市| 仪陇县| 连云港市| 桐城市| 潞城市| 康马县| 伊川县| 穆棱市| 武威市| 天门市| 凉城县| 都匀市| 潜江市| 车险| 洛隆县| 舞钢市| 五家渠市| 慈利县| 饶河县| 芦山县| 永和县| 民县| 房产| 平湖市| 临沧市| 佳木斯市| 甘洛县| 二连浩特市| 衡山县| 印江| 黑河市| 芜湖市| 北辰区|