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').

[EX Q]: Gases are perhaps the best understood of the ____ states of matter.\Question: Choose the right answer from options given a) three b) five c) nine d) zero
[EX A]: a

[EX Q]: Most internal parasites are specific to one or ____ species.\Question: Choose the right answer from options given a) seven b) three c) two d) five
[EX A]: c

[EX Q]: Blood pressure is expressed as ____ different numbers.\Question: Choose the right answer from options given a) ten b) four c) three d) two
[EX A]:
d