TASK DEFINITION: Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').
PROBLEM: Prairie dogs bear four or ____ young per litter.\Question: Choose the right answer from options given a) five b) eight c) two d) zero

SOLUTION: a

PROBLEM: Many scientists believe the neutrino has ____ mass at all.\Question: Choose the right answer from options given a) eight b) zero c) two d) no

SOLUTION: d

PROBLEM: Most adults experience ____ or six sleep cycles each night.\Question: Choose the right answer from options given a) five b) one c) ten d) no

SOLUTION:
a