button-on

He is sewing a button on.

他把一个纽缝了。

First, a general range shall be sketched out with the mouse, then click the function button on the menu, and the program will automatically separate the skull, the hypoderm and the ventricles.

首先用鼠标勾画出大致范围，然后点击菜单项的功能按钮，程序自动除颅骨、皮下组织和脑室。