Add a or an then ask and answer as in the example сделайте это

A]  What's this in English?
It's a ruler.                 
It's a notebook.                  
It's a book
It's  an eraser.               
It's an atlas.                          
It's a school bag.
It's  a pencil case.  
It's a blackboard.   
It's a pen.
It's a pencil.    
It's a notepad.        
It's a timetable.