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: Females have two X-chromosomes, ____ from each parent.\Question: Choose the right answer from options given a) ten b) four c) one d) zero

SOLUTION: c

PROBLEM: Brachiopods are superficially similar to bivalves, both having ____ shells.\Question: Choose the right answer from options given a) two b) eight c) seven d) one

SOLUTION: a

PROBLEM: Oral cancers are about ____ times more common in drinkers than in nondrinkers.\Question: Choose the right answer from options given a) two b) six c) three d) four

SOLUTION:
b