What is the difference between a country and a continent

a country is a part of a Continent, which is a part of the earth

Explanation: in shorter simpler terms there are only a few continent and there are countries around the world

In other words a country is inside a Continent srry if it was 2 long

answer; i believe the correct answer is (a) nigeria is the largest african crude (oil) supplier; /// so revenue from petroleum;