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: Elephants give birth to one calf every ____ to nine years on average.\Question: Choose the right answer from options given a) no b) four c) three d) seven

SOLUTION: b

PROBLEM: Carbon forms ____ bonds.\Question: Choose the right answer from options given a) five b) four c) two d) three

SOLUTION: b

PROBLEM: Minerals have ____ functions.\Question: Choose the right answer from options given a) three b) two c) eight d) zero

SOLUTION:
b