Answer:
you can get more of one good only by giving up some of another good
Step-by-step explanation:
A production possibilities frontier shows the opportunity cost of producing one good instead of another. This way, as you follow the curve, the combination of goods will vary, increasing the production of one good but deceasing the production of the other.
Opportunity costs are the benefits lost or extra costs associated to choosing one activity or investment over another alternative. Since resources are scarce, you must always give something up in order to obtain another thing, e.g. you give up your leisure time in order to study.