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: Every person is a carrier for about ____ rare genetic conditions.\Question: Choose the right answer from options given a) nine b) ten c) six d) three

SOLUTION: b

PROBLEM: Pentatonic scales consist of only ____ intervals.\Question: Choose the right answer from options given a) seven b) five c) six d) one

SOLUTION:
b