Occurs when two species with a close relationship influence each others evolution.

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

Which of th following is needed for cellular respiration to occur

An uncomfortable feeling in the ears when descending in an airplane is caused by changes in air pressure on the: a. inner ear b. middle ear c. eardrum d. hammer/anvil