Questions

The skul contains the bones like Occipital bone, Frontal bone, Mandible, Temporal bone, Parietal bone. The mandible, or jaw bone, is the only movable bone of the skull, forming the temporomandibular joint with the temporal bone. The lower teeth are rooted into the mandible while the upper teeth are rooted in the two maxillae.

A touch screen is the only device which works as both an input and an output device among the given options. You view the options available to you on the screen (output) and you then use your finger to touch the option that you have chosen (input).

Hence, Screen is not purely output device.