3.b
2.c
1.a
4.d
(Check the ileso I might be wrong sorry.)
You can write 3 activities in the first paragraph and the last 2 in the second
Mi mochila no es grande. No cabe todos mis libros.
My backpack is not big. It does not fit all my books.
The verb should be conjugated with the ending -e. This ending applies to he, she, and it nouns. In this case, the backpack was an 'it'.