Scientists can determine if oxygen existed in Earth’s Archean atmosphere by looking for oxidized iron in rock. In the beginning, there was only a little to no oxygen in the atmosphere. The oxygen that are being produced by cyanobacteria is only enough for the weathering process. There will only enough oxygen that shall remain in the atmosphere when the rocks at the surface are properly and adequately oxidized. However, as time goes by, evidences said that the amount of oxygen in the Archean atmosphere is actually increasing in a slow steady pace.
Answer:
D
Explanation:
It was widely believed that Clay, the Speaker of the House, convinced Congress to elect Adams, who then made Clay his Secretary of State. Jackson's supporters denounced this as a "corrupt bargain."
Answer:When we want to find the distance between two integers using the difference, the best way is to plot them on number line. And then count distance between them. For example -3 and -1. But distance can not be negative.
Explanation:
The answer is A The first crusade
Pretty sure its george washington a
