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!
Answer:
A. Obsidian
Explanation:
It fits the property described in the question.
It cools so fast that no visible crystal or grain could form. It has high silica Composition, black and glassy. It is also used to make tools with sharp edges
Salutations!
<span>The Sun belongs to this class of stars?
The Sun belongs to main- sequence stars. Over 90% stars in the universe, which includes the sun are a part of the main sequence stars.
Hope I helped.</span>
