Milankovitch cycles refer to A) cyclical changes in solar ...

[cnetterville]

Milankovitch cycles refer to
 
  A) cyclical changes in solar irradiance caused by increases and decreases in sunspot activity.
  B) tectonic changes in continental position and topographic changes from orogeny, erosion, and mass wasting.
  C) changes in Earth's orbit, axial rotation, and axial tilt.
  D) increases and decreases in atmospheric gases and aerosols, primarily caused by natural activity such as volcanic activity and changes in net primary productivity.

Question 2

Air pollution consists of
 
  A) solely anthropogenic gases, particles, and other substances in amounts that cause damage to the environment or are harmful to humans.
  B) solely natural gases, particles, and other substances in amounts that cause damage to the environment or are harmful to humans.
  C) a distinct class of gases, particles, and other substances that the EPA has deemed worthy of regulating.
  D) both natural and anthropogenic gases, particles, and other substances in amounts that cause damage to the environment or are harmful to humans.

[Carliemb17]

Answer to Question 1

C

Answer to Question 2

D

[cnetterville]

Thanks for the timely response, appreciate it

[Sarahjh]

Wow, this really help