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: Influenza epidemics are ____ times more likely during solar maxima.\Question: Choose the right answer from options given a) ten b) eight c) no d) four

SOLUTION: d

PROBLEM: Mammals have only ____ sets of teeth.\Question: Choose the right answer from options given a) six b) five c) seven d) two

SOLUTION: d

PROBLEM: Brook stickleback have prominent mouths, large eyes and four to ____ spines on their backs.\Question: Choose the right answer from options given a) five b) six c) nine d) ten

SOLUTION:
b