Nitrogen-fixing bacteria in soil can convert excess nitrogen into , which can contaminate groundwater. A/An forms around a well when the water table begins to slope toward the well. The water in an artesian well comes from a/an aquifer. A well not only has to reach the but also has to go deeper. aquifers are more prone to pollution. The two primary components of a septic system are a septic tank and a/an . Groundwater that comes to the surface naturally is known as a/an .

The big bang theory suggest that the universe is about - 300 million years old - 4.6 billion years old - 30 billion years old - 13 billion years old

Astudent completed a lab report. which correctly describes the difference between the “question” and “hypothesis” sections of her report? “question” states what she is asking, and “hypothesis” states the result of her experiment. “question” states what she is asking, and “hypothesis” states what she thinks the answer to that question is in “if . . then . . because” format. “question” describes what she is trying to find out, and "hypothesis" states the procedures and methods of data collection. “question” describes what she is trying to find out, and “hypothesis” states any additional information or prior knowledge about the question.

What is referred to as universal solvent due to which factors?