If all atoms in a molecule of a substance or a lake in the substance is A mixture B compound C solid D element. 

Which is an example of a decomposer? a. bear b. algae c. grass d. bacteria d bacteria

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

Which measure of an earthquake depends on how close you are to the focus?