The correct answer is - cyanobacteria.
The atmospheric oxygen came from the cyanobacteria. These were one of the earliest living organisms on Earth. The cyanobacteria was using photosynthesis in order to create its own food. The photosynthesis process requires sunlight, carbon dioxide, water, and oxygen. The oxygen is mostly released as a waste product from the process of photosynthesis, thus the cyanobacteria were literally releasing oxygen that was ending up into the atmosphere. As more and more cyanobacteria there were across the planet, more and more oxygen they were releasing into the atmosphere, slowly changing the composition of the atmosphere, and setting the basis of it as we know it now.
Answer:
D. Most European nations are part of the European Union.
Explanation:
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ANSWER: A country with a high rate of natural population increase, where food supplies are at risk
Answer:
Eritrea has faced several challenges since gaining independence from Ethiopia in 1993. The country has only one political party that maintains all of the control. Democratic national elections have yet to be held; the transitional government is still in power, and no constitution has been implemented. Furthermore, territorial disputes with Ethiopia continue. Eritrea's command economy is struggling. Over 80% of the population is engaged in subsistence agriculture. Climate changes have created problems for agriculture, and drought is a major issue. Finally, property damages due to war have proven costly.
Explanation:
That is the correct sample response.
Answer:
There are 54 countries in Africa, today.
Explanation:
