Final answer:
A seesaw is an example of a first-class lever.
Step-by-step explanation:
A first-class lever is a type of simple machine where the fulcrum is located between the effort and the load. One example of a first-class lever is a seesaw. In a seesaw, the fulcrum is at the center and the effort is applied on one end, while the load is on the other end. When one person pushes down, the other person goes up.
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