Open Word, select everything with the mouse, and click on the top (Start) (Center) to center.

The mouse is the external input device of the computer and the indicator of the vertical and horizontal coordinate positioning of the computer display system, so it is named because it looks like a mouse (Hong Kong and Taiwan are mice). Its standard name should be "Mouse" and its English name is "mouse". The use of the mouse is to make the operation of the computer easier and faster, rather than the tedious instructions of the keyboard.