Which of the following human activities contributed to the ...

[kamilo84]

Which of the following human activities contributed to the pollution of our ancestral air?
 
  A) Discovering, making, and using tools contributed to air pollution.
  B) The discovery and use of fire contributed to air pollution.
  C) The development of crop farming contributed to air pollution.
  D) All of these contributed to air pollution.

Question 2

Petroleum jelly is
 
  A) a mixture of low carbon number hydrocarbons.
  B) a mixture of moderate carbon number hydrocarbons.
  C) a mixture of higher carbon number hydrocarbons.
  D) none of the above

[perkiness]

Answer to Question 1

D

Answer to Question 2

C

[kamilo84]

Excellent

[JaynaD87]

Thanks for the timely response, appreciate it