Examples of a force are: gravity, friction, pushing a door with your hands, pulling a box, the electric force responsible for the interaction of charged objects, the magnetic force, etc.
(Examples of a force; are; gravity, friction, pushing a door with your hands, pulling a box) (gravity, friction; pushing; a door; with your hands) (gravity, friction; pulling; a box)
Examples of a force gravity, friction gravity, friction
are pushing pulling
gravity, friction, pushing a door with your hands, pulling a box
a door with your hands
a box