(a) In squeezing a piece of lemon, we make use of muscular force to extract its juice. This muscular force acts on the lemon. As a result, the shape of the lemon gets changed.
(b) We use our muscular force to take out paste from a toothpaste tube. The muscular force acts on the toothpaste tube. As a result, the shape of the tube gets changed.
(c) Here, the suspended load exerts a force on the spring and pushes the spring downwards. As a result, the spring gets stretched. Hence, its shape gets changed.
(d) Agent is muscles of athlete, object is athlete himself and effect of the force changes the state of motion of the athlete.