All of the following describe a passive solar energy system EXCEPT A. heat is mechanically moved to a storage area for use at a later time.
B. architectural designs are major components to the system.
C. the systems have been used for the past 1000 years or so.
D. the systems function without mechanical power.

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primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.