Matter {Ans: Everything that takes up space and has mass is ____________.}Streambank erosion {Ans: ____________: This is a problem in farmland streams, where soil washes away from streambanks.}Critical Thinking {Ans: _________: A term we use to describe logical, orderly, analytical assessment of ideas, evidence, and arguments.}Natural Experiment {Ans: This involves observation of events that have already happened.}Barrels {Ans: Oil is measured in ___________.}Non-point Source {Ans: Fugitive, or __________, emissions are those that do not go through a smokestack.}