Clouds with extremely cool water are mixed with man-made ice crystals, such as silver iodide and metaldehyde crystals.

VOA: special.2011.01.11

There was the wonder I felt when I saw a brace of mountain like, spotted, black-and-white horses clopping down a dusty road through clouds of powdered clay.

我觉到很美妙,当我望见一大群如山般高大的，黑白斑点马压过土路,我觉到很快乐。

耶鲁公开课 - 1945年后的美国小说课程节选

The Clouds was written in 423 when Socrates was in his mid-forties and the Aristophanic Socrates is essentially what we call a natural philosopher.

云》剧写于公元前423年3,当时苏格拉底约45岁,亚里斯多芬尼斯时的苏格拉底,基本上就是我们所谓的自然哲学家。

耶鲁公开课 - 政治哲学导论课程节选