Essential Part - Verbal and Reasoning

Directions to SolveA good way to approach this type of question is to use the following sentence: "A ______ could not exist without ______.". Find the word that names a necessary part of the underlined word.
Q1:

vibration

A motion

B electricity

C science

D sound

ANS:A - motion

Explanation: Something cannot vibrate without creating motion, so motion is essential to vibration.