A roll cloud is "a long, low tube of a cloud," sometimes smooth, sometimes bumpy.

卷云是“一种低矮的长管形云彩，”它时而平滑，时而臃肿。

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A roll cloud is "a long, low tube of a cloud," sometimes smooth, sometimes bumpy.

卷云是“一种低矮的长管形云彩，”它时而平滑，时而臃肿。

youdao