常見例句Sometimes these clouds are so extensive that they are virtually indistinguishable from one another, forming a sheet of cirrus called cirrostratus. 卷云是高云的一種,是對(duì)流層中最高的云,平均高度超過6000公尺。cirrostratus nebulous 薄幕卷層云cirrostratus nebulosus 薄幕卷層云cirrostratus cloud 卷層云 返回 cirrostratus