What distinguishes push-ups from other chest exercises such as the bench press and dumbbell flies?

Owners-Pets.

Explanation:

The one-to-many relationship in database is when each record in Table A have several linked record in Table B. But in Table B, it has only one link in Table A.

An example of a one-to-many relationships is owners-pets relationship. In such databases, pet will have one owner but one owner may have many pets.

Therefore, owners-pets is an example of one-to-many relationship.