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

It is just a notation to remind us closed surface.

这就是一种提醒我们曲面是封闭的的记号。

youdao

It is just a notation to remind us closed surface.

这就是一种提醒我们曲面是封闭的的记号。

youdao