把下列中文翻译成英文，不要软件翻译的！！

大家不要乱翻译吧，会的帮一帮，不会的不要乱刷分。不好啊。

1.projection of the region of curved surface on the coordinate plane

2.cross-section method.
（这是专业名词，cross-section theorem是截痕原理）

截痕法是数学与机械工程学专业中的专有名词，这个词组是我问的一位正在读研的师兄。
截痕法:law of cross-section

由曲面所围立体在坐标面上的投影区域：a projected tolerance zone encircled by solid that is surrounded with curved surface on the planeofcoordinates

这段话实在是难翻译...全是生词...还好我有师兄指点,不算太困难.

Encircles by the surface three-dimensional on the coordinate plane projection region

截痕法：Truncation mark law

由曲面所围立体在坐标面上的投影区域

Projection area of the coordinate face that surrounded with curve face.

projection of the region encircled by a surface on the coordinate plane

截痕法：method of sections

由曲面所围立体在坐标面上的投影区域:
Wai from the surface in three-dimensional coordinates of the projection surface area.
截痕法:Cut-off mark law