The solar system formed from the ?
a. collision of two massive stars.
b. grouping together of asteroids.
c. collapse of an interstellar cloud.
d. explosion of an interstellar sun.

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?