command+shift+control+3截取全屏幕存在剪贴板，command+shift+control+4选择区域截图存在剪贴板，command+shift+control+4选择区域截图存在剪贴板，command+shift（+control）+4时对准窗口按空格键可以选择窗口截图。command+shift+control+3截取全屏幕存在剪贴板，