Question

put the sentenses into the plural  form
 a ) what is this ?
b)This is an eraser .
c)That is pen
d)What is that 
e) this is a ruler
f)that is a pen

Answer 1

a. what are these?
b.these are an erasers.
c. those are pens.
d. what are that. 
e. These are  an rules.
f.Those are an pens