The agency examines and coordinates the clean up of polluted sites. environment protection

The correct answer for the blank is- Environment Protection agency.

The Environmental Protection Agency is an independent body of the United States federal government that was established in 1970 for the protection of environment (from various pollution as such air pollution, water pollution) as well as the health of human beings (from the harardous consequences of toxic chemicals and pollution).

This agency performs a regular examination and coordinates to clean up various polluted sites in the environment.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.