Mark was sitting in the most comfortable armchair when he heard the strange noise again.He heard that noise yesterday when he was reading a book.But what was it?

He stood up and came up to the window.It was raining.The wind was blowing.Mark saw nothing strange.Then he went to his bedroom.He switched on the light,but nothing strange was in the room either.He decided to look into the kitchen.And suddenly he saw his favourite dog.It opened the fridge and was eating sausages with great appetite.

How had it managed to open the fridge ?Mark couln't understand!