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: Today there are ____ federal states, each based on cultural affiliations.\Question: Choose the right answer from options given a) one b) nine c) seven d) zero

SOLUTION: b

PROBLEM: Altimetric satellites are usually limited life missions lasting approximately three to ____ years.\Question: Choose the right answer from options given a) five b) ten c) four d) eight

SOLUTION: b

PROBLEM: Most aphthous ulcers heal in one to ____ weeks.\Question: Choose the right answer from options given a) two b) eight c) one d) seven

SOLUTION:
a