Aquifers are .

a. located below the water table

b. important sources of freshwater

c. located in the saturated zone

d. all of the above

Which of the following choices is not an effective solution to the energy waste related to inefficient lighting? a. using low-pressure sodium lighting sources b. pointing lights on billboards and street signs upward c. placing light sources on time controls d. shielding light to direct it downward

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?

Approximately percent of the energy created by cell metabolism is used by the body to carry on its normal functions, such as respiration, digestion, reproduction, muscular movement, circulation, and cellular regrowth.