File -> Change working directory
permanent working directory:
proe快捷方式->属性->起始位置，修改为工作空间目录
Translation and rotation
5.按住[中建]不放：旋转对象
6.Shift+[中建]不放：平移视图
Close and remove the old version
close: file->erase->current
delete old version: file->delete->old version