【单选题】

Observe the dilemma of the fungus: it is a

plant, but it possesses no chlorophyll. While all
other plants put the sun’s energy to work for them
Line combining the nutrients of ground and air into the
(5) body structure, the chlorophylless fungus must
look elsewhere for an energy supply. It finds it in
those other plants which, having received their
energy free from the sun, relinquish it at some
point in their cycle either to animals (like us
(10) humans) or to fungi.
In this search for energy the fungus has
become the earth’s major source of rot and decay.
Wherever you see mold forming on a piece of
bread, or a pile of leaves turning to compost, or a
(15) blown-down tree becoming pulp on the ground,
you are watching a fungus eating. Without fungus
action the earth would be piled high with the dead
plant life of past centuries. In fact, certain plants
which contain resins that are toxic to fungi will
(20) last indefinitely; specimens of the redwood, for
instance, can still be found resting on the forest
floor centuries after having been blown down.
The author is primarily concerned withA．warning people of the dangers of fungi
B．writing a humorous essay on fungi
C．relating how most plants use solar energy
D．describing the actions of fungi
E、explaining the long life of some redwoods