It depends on where you live. Try both and compare. You can delete an app you don't want.
Answer:
to provide a reference system
Explanation:
The equator and prim meridian used on maps provides a reference system for determining location and navigating the earth.
- An equator is the only line of latitude that is a great circle.
- Prime meridian is a line of longitude that is 0°
- When both are used, they can form the basis of a reference system to determine places on earth.
- Using these lines, we can assign values of coordinates to the earth surface to facilitate location determination.
The equator and prime meridian are used on maps to provide a reference system.
Niger and Congo are two rivers after which countries are named (actually in both cases two countries each) - and those are African countries, so they must be in Africa.
Zambezi is a river in Angola and Namibia.
Tigris is a River in Mesopotamia, in Asia - so that's the correct answer!
