Pictures:

What starts with P and ends with E and has thousands of letters.

Post Office.

956

What do you call a train carrying bubble gum?

A chew-chew train.

959

What is blue and smells like red paint?

Blue paint.

974

What invention lets you look through a wall?

A window.

960

What is full of holes but still can hold a lot of water?

A sponge.

967