Question

pliiis es urgente cambiar a plural
this is a rabbit --- this is a fly --- that is a horse --- that is an ostrich

cambiar a singular
these are mice --- those are children --- these are butterflies --- those are monkeys

Answer 1

Plural: 

These are rabbits 
These are flies 
Those are horses 
Those are ostriches

Singular: 

This is a mouse 
That is a Child 
This is a butterfly 
That is a monkey 

Answer 2

this is a rabbit: there are two rabbits