Gray matter is what this consists of
There are 3 controlled variable
Answer is D Whereas theDepartment of Defense is charged with military actions abroad, theDepartment of Homeland Security works in the civilian sphere to protect the United States within, at, and outside its borders. Its stated goal is to prepare for, prevent, and respond to domestic emergencies, particularly terrorism.
The answer that contributes to Mars's cool temperatures is the third choice - Its thin atmosphere and distance from the Sun.
Mars is relatively distant from the Sun - it is the fourth planet away from the Sun which means that it can be quite cold there given that its atmosphere is quite thin which means that the cold is quite present there.
Answer:
2.7 billion
Explanation:
This period is referred to as the Great Oxygenation Event. This period saw the evolution of photosynthetic organisms (cyanobacteria) that utilized carbon dioxide (that dominated the atmosphere then) and sunlight to manufacture their energy molecules-glucose. Photosynthesis produces oxygen as a byproduct that is evolved into the atmosphere. As these photosynthetic organisms proliferated on earth, the atmosphere composition changed to become partly dominated by oxygen (which is an oxidaton agent) with less and less carbon dioxide.
