Acids constitute a family of (chemical compounds) that, (in) (solution), have the ability to turn certain blue vegetable dyes red, a corrosive action on metals, and (taste sharp).

单项选择题Greeley's injunction Go West, young man resulted in a massive migration of population, with people occupying land ______ no one held title of ownership and that had yet to be sold.

单项选择题Obviously, he decided not to say anything about it because he hoped to ______.