OE


The blank is describing the conditions of life. The sentence gives further insight into the blank by listing examples of what the conditions of life could be, such as…atmospheric pressure…physical activity, and diet. These clues imply that the conditions of life are “varying.” Choice (A), inveterate, means have a long-standing habit, so eliminate it. Choice (B) is a good match for the blank, so keep it. Choice (C), timorous, means nervousness, so eliminate it. Choice (D), cowed, means to pressure by intimidation, so eliminate it. Choice (E), turgid, means swollen, so eliminate (E). Choice (F) is a good match for the blank, so keep it. The correct answer is (B) and (F).