我需要两个图层是为了精确地控制两个范围小石子的分布——从边石到远距离和第二个从逐渐增加的石子密度到边石。

I needed two layers to precisely control small stones distributing with two ranges - from curbs to distance and the second to increase density of stones close to the curbs.

youdao

尽管南北两缘面对面相隔只有12公里，可是坐车从一边到另一边的距离却是214公里。

Though the two rims face each other across only 12 miles, it is a journey of 214 miles by car from one to the other.

youdao

尽管南北两缘面对面相隔只有12公里，可是坐车从一边到另一边的距离却是214公里。

Though the two rims face each other across only 12 miles, it is a journey of 214 miles by car from one to the other.

youdao