Within soil, a natural cycle of A) decomposers break down ...

[james0929]

Within soil, a natural cycle of
 
  A) decomposers break down detritus to release nutrients used by producers.
  B) detritus breaks down by the action of weak soil acids to release nutrients used by producers.
  C) decomposers break down nutrients to release detritus used by producers.
  D) decomposers break down detritus to release nutrients used by consumers.

Question 2

How does evidence from seismic tomography support the hypothesis of mantle convection?
 
  What will be an ideal response?

[kristenb95]

Answer to Question 1

A

Answer to Question 2

Mantle convection will result in areas that are hotter and less dense than their surroundings. These areas would have lower P and S wave velocities. A map of S-wave velocities shows areas of lower velocity that are presumably areas where the mantle is hotter and rising.