Question

biological carbon acts on a timescale of ________ of years.
a hundreds
b thousands
c millions
plants, algae and phytoplankton are the main components of the ______ carbon cycle.
a fast
b slow
what two recurring events in earth’s history have an impact on the carbon cycle?
a earth’s orbit and climate change
b solar events and eclipses

Explanation:

Biological carbon cycle processes (e.g., photosynthesis, decomposition) operate on timescales of hundreds of years. Plants, algae, and phytoplankton are key to the fast carbon cycle. Earth's orbital variations and climate change are recurring events affecting the carbon cycle.

Answer:

A. hundreds, A. fast, A. Earth's orbit and climate change