Question

complete using there is ou there are;

                   book in my backpack
                   a bike here
                   pencils  in my case
                   eggs in this box
                   cats at the petshop 

Answer 1

There is - usado no singular
There are - plural
1- There is a book in...
2 - there is a bike...
3- There are pencils...
4- there are eggs...
5- There are cats...

Answer 2

There is a book in my backpack
 There is a bike here
There are pencils in my case
There are eggs in this box
There are cats at the petshop