In nutrient cycles in general, minerals tend to be dispersed through ________.
A) plant action
B) surface and subsurface runoff
C) evaporation
D) assimilation
E) conduction
Question 2
For about the last ________ years, Earth has had about the same balance of chemical components that now persists.
A) 10,000
B) 100,000
C) 1 million
D) 500 million
E) 1 billion