Many of our basic biological functions, such as breathing, exist at the level.
a. preconscious
b. nonconscious
c. unconscious
d. conscious

B. Nonconcious many of the things we do without thinking about fall into this category

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.