What method of pest control operates on the principle that "the enemy of one's enemy is one's friend"?

As our current atmosphere formed, the concentrations of various atmospheric gases fluctuated. match each gas with the explanation that best describes how its proportion changed during the evolution of the atmosphere.

You think all professors are uncoordinated, but then you see your social psychology professor make a diving catch down the left-field line at an intramural softball game against the arts department team. you also notice that your professor hits lead-off for the team and is able to score from second base on a ground-out. you maintain your original stereotype of professors as uncoordinated by deciding that this one individual is an exception to the rule because he is a “young professor.” this is an example of

For 50 pointsfredrika's science teacher asked her to bring in three abiotic items from her backyard ecosystem. which of the following groups of items should she bring? a. a lightning bug, a plug of grass, and a wormb. a smooth rock, some red dirt, and an empty bird's nestc. a ladybug, a spider, and some water from a mud puddled. a caterpillar, a pine cone, and a piece of a robin's egg