C. summer the answer is summer
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!
Photovolatics utilize "Solar" energy to produce electricity.
Answer:
A small metallic core of high density with one quarter of its mass composed of water and ice.
Explanation:
Piedmont, Genoa and Nice came to be united