Three men , one on a ladder , work on a roof .
The men are laying in a pool .
Three men, one on a ladder, work on a roof.
The men are laying in a pool.
Doing work on a roof means that you are on top of a building performing an activity, you are not laying in a pool which means being in the water an inactive.
Doing work on a roof means that you are on top of a building performing an activity , you are not laying in a pool which means being in the water an inactive .