Environmental spills of petroleum are sometimes cleaned up by using?
a) protists
b) viruses
c) bacteria
d) bacteriophages

Which sequence correctly shows the path of carbon dioxide during repiration?

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

Which phrase is the best summary of the model shown? a. the transfer of the sun's energy through trophic levels b. a series of aerobic and anaerobic reactions c. a transformation of light energy into chemical energy d. the breakdown of food molecules