Arrange the words given below in a meaningful sequence.
1. Key
2. Door
3. Lock
4. Room
5. Switch on

1. Key: A key is used to open a lock.
2. Lock: The lock is attached to a door.
3. Door: The door provides access to a room.
4. Room: Once inside the room, you might need to turn on the light.
5. Switch on: Finally, you switch on the light.

Therefore, the meaningful sequence is Key, Lock, Door, Room, Switch on.