It is fine.It is a closed surface.

这是一个封闭曲面。

youdao

So, s is actually this whole closed surface here.

那么，S实际上是这个完整的封闭曲面。

youdao

So, s is actually this whole closed surface here.

那么，S实际上是这个完整的封闭曲面。

youdao