The U.S. Border is considered to be a public good, while the satellite TV is a private good. The satellite TV is considered to be a private good, since the citizens purchases its services in order for them to acquire entertainment, while the US border does not require any payment in order to get its services, its already a requirement that every citizen must undergo in passing.
it mad the soil become salty making it hard for crops to grow
The answer would be D because Pre-Columbian civilizations didn't have any domesticated animals such as cows, chickens, and horses. This fact limited the accessibility to meat for the Pre-Columbian civilizations.
