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:
crust- the earth's outmost layer
inner core- the metallic layer at the earth's center
lower mantle- hottest part of the mantle
asthenosphere- the semi solid layer between the top layer and the upper mantle
upper mantle- The layer between the asthenosphere and lower mantle
top layer- The firm layer between the crust and the asthenosphere
outer core- The layer surrounding the inner core
Explanation:
The Wisconsin River originates in the forests of the North Woods Lake District of northern Wisconsin, in Lac Vieux Desert near the border of the Upper Peninsula of Michigan. It flows south across the glacial plain of central Wisconsin, passing through Wausau, Stevens Point, and Wisconsin Rapids. In southern Wisconsin it encounters the terminal moraine formed during the last ice age, where it forms the Dells of the Wisconsin River. North of Madison at Portage, the river turns to the west, flowing through Wisconsin's hilly Western Upland and joining the Mississippi approximately 3 miles (4.8 km) south of Prairie du Chien.
The proximity of water was an advantage to Western Europe and its culture was able to flourish as a result. Trade and travel by sea were easier and safer in historical times.
Answer:
False
Explanation:
A tornado watch is issued when the conditions are ideal for a tornado to form and covers a broad region. Tornado warnings are when a tornado has been spotted or appears on the radar.
