PSAT Reading Question 98: Answer and Explanation

Question: 98

As used in line 37, "undulation" most nearly means

• A. attraction.
• B. evaporation.
• C. undertow.
• D. ripple.

Correct Answer: D

Explanation:

D

The question asks what the word undulation means in line 37. Go back to the text, find the word undulation, and highlight it. Carefully read the surrounding text to determine another word that would fit in its place, based on the context of the passage. The text says that spherical particles…do not substantially deform the air-water interface. Ellipsoid particles, however, cause substantial undulation of the air-water interface. Therefore, undulation must mean some kind of "change of shape." Neither attraction, evaporation, nor undertow mean "change of shape," so eliminate (A), (B), and (C). A Ripple is a "change in shape," so keep (D). The correct answer is (D).