The telephone :   how does it work. 

 - 21 pages :   colour illustrations ;   21 cm 
 - My ICT data bank series .
 - My ICT data bank series .
<br/><br/> Includes glossary 
<br/><br/><label>ISBN: </label>9831502272 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephone.
<br/><br/><label>Dewey Class. No.: </label>621.385