A closed water bottle is flipped upside-down, causing the liquid inside to fall. in one sentence

Flipping the closed water bottle upside-down causes the liquid inside to pour out.

When a closed water bottle is flipped upside-down, the liquid inside falls due to the force of gravity and the air pressure pushing on the outside of the bottle.

When a closed water bottle is flipped upside-down, the liquid inside falls due to the force of gravity acting on it.