18.It has been said that knowledge is power, but greater power lies in the ability to utilize knowledge. A trained and powerful mind surely contains something, but its chief value consists in what it _____.
(A) contains
(B) can do
(C) forgets
(D) retains

14.In the United States, Arbor Day is a day for planting trees. Most states Celebrate Arbor Day, and in some states the day is a legal holiday. The date varies among the states because the best time for tree planting depends upon _____. (A) climate (B) convenience (C) population (D) available forests

15.People who have nothing to boast of but their illustrious ancestors are like a potato—the only good belonging to them is _____. (A) good to eat (B) dirty (C) the future (D) underground

16.Ignorance is the mother of suspicion. We can rid ourselves of our suspicions only by _____. (A) analyzing them (B) brooding over them (C) forgetting their existence (D) procuring more knowledge

17.Our bodies need food and oxygen, and these must be supplied constantly. Food can be stored in the body, so a person need not eat all the time in order to satisfy this requirement. Our bodies cannot store oxygen; therefore, _____. (A) food is harder to find than is oxygen (B) we must keep looking for new supplies of oxygen (C) we must keep breathing all the time (D) oxygen is more important than food

19.Often, the purchase of one fine thing requires the purchase of several more so that your appearance may be all of a piece. Poor Richard says, “It is easier to suppress the first desire than to _____.” (A) decide what should follow (B) satisfy all that follow it (C) have to borrow money (D) consult your purse

20.Never accept as fact something for which there exists only partial proof. Recognize as true only that which is demonstrated clearly enough to eliminate all reasonable _____. (A) truth (B) research (C) doubt (D) verification

21.This passage is concerned with (A) healthy people and doctors. (B) bleeding as a cure-all. (C) barbers of long ago. (D) leeches with special jobs to do.

22.The red and white stripes on barber poles symbolize (A)sin and redemption. (B) the bleeding ritual. (C) women who are nurses. (D) humors in the body.

23.Why is bloodletting no longer considered a cure-all? (A)Because more is known about the workings of the human body (B) Because leeches were outlawed (C) Because barbers were too busy cutting hair (D) Because today we know that blood is necessary for health

24.In the second paragraph, the word “thus” could be replaced by the word (A) when. (B) however. (C) if. (D) so.