They used the sun to see what time it was by putting there hand by the sun and counting each our as the sun goes up.
Answer:
D. any two categories of goods
Explanation:
The Production Possibilities Curve is used to represent graphically different production possibilities in a certain economy. It measures the maximum output of two goods, any kind of goods, this by using a fixed amount of input.
Basically it shows us how much of a good can be produced when another good is produced too using some of the same resources.
