What can cause the regional or local extinction of species, or shifts to
different ecosystem communities.?*

(A)droughts

(B)weather cycles

(C)global warming

(D)large volcanic eruptions

answer increasing the intensity, duration,and frequency of exercise progressively;

other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. the si derived unitsfor these derived quantities are obtained from these equations and the seven si base units.

sounds like the answer you're looking for is spores.