help!!! 識電腦嘅人請come!

Keyboard is an input device partially modelled after the typewriter keyboard which uses an arrangement of buttons, or keys which act as electronic switches.

Printer is a peripheral which produces a hard copy (permanent human-readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or transparencies.

CD-ROM (Compact Disc Read-Only Memory) is a pre-pressed Compact Disc that contains data accessible to, but not writable by, a computer.CD-ROMs are popularly used to distribute computer software, including games and multimedia applications, though any data can be stored.