The overall rate at which humans are producing carbon dioxide is ...

[crobinson2013]

The overall rate at which humans are producing carbon dioxide is ________.
 
  A) increasing
  B) decreasing
  C) some years increasing and other years decreasing
  D) remaining about the same

Question 2

What determines the direction of heat flow?
 
  A) Heat always flows from a lower-temperature substance into a higher-temperature substance.
  B) Heat always flows from a higher-temperature substance into a lower-temperature substance.
  C) Heat flow direction depends upon the density of the substances involved.
  D) The direction of heat flow is not predictable in any given process.

[fauacakatahaias]

Answer to Question 1

A

Answer to Question 2

B