In the past 100 years the average temperature in the united states has increased by
a. an amount too small to measure.
c. 10°
c.
b. 2°
c.
d. 20°
c.

2 degrees

Explanation:

In the past 100 years the increase in the average temperature is 2 degree. This is because of the global warming that there is a increase in the overall temperature.

The release of more and more carbon dioxide in the environment has lead to increase in the absorption of solar radiation.

The carbon dioxide has the ability to absorb heat from the atmosphere. More carbon dioxide will trap more heat from the atmosphere and thus increasing the global temperature.

they deliver oxygen to the blood

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.