translation.en: And for me, I quickly landed on this one: The Earth has a tolerance of about .17 percent from the reference spheroid, which is less than the .22 percent allowed in billiard balls.
translation.zh: 对我来说，我很快的看到了它： 地球离参考椭球有着大概百分之0.17的公差， 比桌球的百分之0.22标准更小。