An ecosystem is best described as A) a system that is composed ...

[Jipu 123]

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

[Carliemb17]

Answer to Question 1

Answer: C

Answer to Question 2

Answer: B

[Jipu 123]

Wow, this really help

[frankwu0507]

Thanks for the timely response, appreciate it