每次都會忘記，在這邊筆記一下…
command + shift + 3 -> print screen in mac os x
command + shift + 4 -> print patial of screen in mac os x
command + shift + 4, space -> print screen on an app window in mac os x
以上都會存成檔案，如果只要寫進剪貼簿的話，加一個shift就好了；
如果是在bootcamp的Windows裡的話，
shift + f11 = print screen
alt + shift + f11 = print screen on an app window in mac os x
(notice that you might press fn key to enable the original f11 feature)
