Force and pressure

In the following situations identify the agent exerting the force and the
object on which it acts. State the effect of the force in each case.
(a) Squeezing a piece of lemon between the fingers to extract its juice.
(b) Taking out paste from a toothpaste tube.
(c) A load suspended from a spring while its other end is on a hook fixed
to a wall.
(d) An athlete making a high jump to clear the bar at a certain height.