A cloud is made of billows upon billows upon billows that look like clouds. As you come closer to a cloud you don't get something smooth, but irregularities at a smaller scale.
云是由一层又一层的波纹构成的，这些波纹看起来像云。当你靠近一朵云的时候，你不会得到平滑的物体，而是在更小的尺度上不规则的物体。
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