add paper switch的用法和样例：
- Easy to load paper, convenient for user to add paper and remove paper stopper?
- The operation of a simple paper feed printer is just like that of duplicator. It is very easy to operate and to add paper stock without stopping the machine.
- If you add paper but still receive an out-of-paper message, check the print options for the document to see if you've selected the correct paper tray or source.
- If the sleeve is taken in, the armhole must be correspondingly reduced by adding paper to the underarm as shown by the shaded portion in the diagram.