sentences: friction causes the temperature of an object to increase & friction occurs when two object 's surfaces move against each other ->  when friction occurs between two objects, both objects' temperatures increase  a wooden block is pushed across a sheet of sandpaper & an object being pushed across another object causes their surfaces to move against each other ->  the surfaces of a wooden block and sandpaper are moving against each other  the surfaces of a wooden block and sandpaper are moving against each other & friction occurs when two object 's surfaces move against each other ->  friction occurs when the wooden block is moving against the sandpaper  when friction occurs between two objects, both objects' temperatures increase & friction occurs when the wooden block is moving against the sandpaper -> friction will cause the temperature of the wooden block to increase