回复: “国家地理杂志”教你如何观云彩！
Photo Gallery: Clouds
Light, fluffy clouds stretch across the broad sky of South Africa's Kalahari Desert. Most clouds are produced by the upward motion of air, which may be caused by weather or local topography.
意译：云彩的图片画廊。日光，蓬松的云彩伸展横跨广阔的天空在南部非洲的卡拉哈里沙漠。 大多数云彩是由向上运动的空气引起，这可能是由于天气或当地的地形学。
