An ecosystem is best described as
A) a system that is composed of nonliving or inorganic matter.
B) a system composed of living organisms.
C) a group of living organisms and the abiotic spheres with which they interact.
D) all living organisms in the atmosphere, hydrosphere, and lithosphere.
E) a group of living plants and the soil types that is present.
Question 2
What is the difference between density and concentration? Density is the ________ with which something occurs in ________, and ________ is the extent of a feature's spread over space.
A) space, concentration, frequency
B) frequency, space, concentration
C) period, space, time
D) period, concentration, space
E) frequency, time, space
The Uranus System
Solar System
Color monitor for a computer system.
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The Digestive System
Overview of the Solar System