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: Teething begins for most babies around ____ to six months.\Question: Choose the right answer from options given a) three b) four c) five d) seven

SOLUTION: b

PROBLEM: Electrolytic capacitors have a useful life of about ____ years.\Question: Choose the right answer from options given a) ten b) eight c) zero d) seven

SOLUTION: a

PROBLEM: Salvinia plants are floating ferns, there are only ____ species in the world.\Question: Choose the right answer from options given a) nine b) ten c) three d) one

SOLUTION:
b