The appearance of banded iron layers in the rock record between 1.08 and 3.8 billion years ago reflect the alteration of oxygen-rich and oxygen-poor conditions in the ocean at that time is True.
<u>Explanation:</u>
The banded iron formation of the rock is directly related with the atmospheric oxygen content of that time. The thorough study by the scientists revealed an interesting result. The study showed that about 3 billion years ago, in Canada, there were no oxygen in atmosphere or ocean as well.
This resulted in the increase of the photosynthesizing organisms. The chemicals released from the organisms reacted to the iron of the ocean to deposit iron oxide layer on rocks to form these layers.
Fracking can contaminate water supplies if it is not done properly, because the fracking fluid injected into rock to enable gas to be released often contains chemicals. If the borehole is not properly cased to stop leaks, the fracking water can escape into the aquifer
-The name of the general was Leslie Richard Groves Jr. He Graduated fourth in his class<u><em> in the U.S. Military Academy at West point.</em></u>
<h3><u>Explanation;</u></h3>
<u>The name of the general was Leslie Richard Groves Jr. He graduated from the United States Military Academy of West point in the year 1918.</u>
As an engineering aide, He led a small team of workers who helped produce the exterior casing of "Fat Man," a nuclear bomb dropped on Nagasaki, Japan, that hastened the Japanese unconditional surrender three weeks later.
