What did ancient Chinese chemists discover when trying to find the elixir of immortality?

Which best describes why it is necessary to evaluate a solution?

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

The cause and events that led to civil rights