This is not social studies. may I suggest chemistry or biology.
Answer:
a the air near the ground is cooler than the air directly above it.
Explanation:
A temperature inversion occurs when the air near the ground is cooler than the air directly above it. That is, when temperature normally is supposed to be reduced by an increase in altitude, instead it increases.
Well, the U.S. Currency is backed by the assets of the Federal Reserve Bank. (it was gold till 1934), and out of the options given the best is d. the federal government.
