Inside. Behind

ANSWERS

1. 
   Inside is a type of preposition which means in or into a building, room or any kind of closed space.
   

For example: It is raining. We shall have to go inside.

2. 
   Behind is also a type of a preposition which means at or towards the back of a thing or a person.
   

For example: I turned to the person standing behind me.

3. 
   Beside- is next to or very close to the side of someone or something.
   

For example: Wandy came up and sat beside me

4. 
   Through- into one side or end of an entrance, passage, hole and out of the other side or end.
   

For example: She smiled at him as he walked through the door.