Well, you just take a closed curve in the plane.

只需在区域中取一条封闭曲线。

youdao

If we have a closed curve then the line integral for work is just zero.

如果给定一条封闭曲线，那么求所做功的线积分为零。

youdao

Also, a new method of the representation of closed curve is given.

同时得到了一种闭曲线表示的新途径。

youdao

Also, a new method of the representation of closed curve is given.

同时得到了一种闭曲线表示的新途径。

youdao