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: Avian kidneys have ____ kinds of nephrons.\Question: Choose the right answer from options given a) four b) eight c) no d) two

SOLUTION: d

PROBLEM: Fruit trees are usually safe after ____ years.\Question: Choose the right answer from options given a) five b) four c) no d) three

SOLUTION: d

PROBLEM: Ostriches usually live in groups, most commonly one male with ____ females.\Question: Choose the right answer from options given a) nine b) three c) ten d) eight

SOLUTION:
b