英语翻译
1.theheightoftheatmosphereisabout30km.theradiusofearthis6400km.whatpercentageofearth'sradiusistheheightoftheatmosphere?
2.howwouldthedensityofairatthebottomofadeepmineshaftcomparetothedensityoftheatmosphereatthesurfaceoftheground?
邮箱:联系方式: