Lol sorry just now I forgot to out my name in the title ^_^''
Pic 1: The scissors is a lever that transfers the force effectively to cut certain objects.
Pic 2: Linkages and levers connect with each other to support the table and allow it to be folded.
Pic 3: The gears and chain and sprocket in a bicycle help to transfer the force to let the bicycle move effectively.
Pic 4: The bicycle gear is damaged and as shown in the picture, it is hanging downwards. The last picture is my solution to this problem with explanations in the picture..