Giving brainliest civics btw (social studies)

Federalism began to spread super soon after

Commercial agriculture consists of raising food for trade and profit, while subsistence agriculture focuses on -- a. providing the basic needs of the farmer's family b. providing the basic needs of the neighboring communities c. creating more arable land for future use d. obtaining subsidies from governments and corporations

Katie and her father are looking at the pipes around their house. they find that some of the pipes have rust on them, making them look and feel different than normal pipes. what kind of change have the rusted pipes gone through? a. a physical change b. a vibration change c. a chemical change d. a temperature change