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: 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

SOLUTION: a

PROBLEM: Water is the only natural substance which exists in all ____ states of matter in nature.\Question: Choose the right answer from options given a) no b) eight c) six d) three

SOLUTION: d

PROBLEM: Buttercups have ____ to six petals or sepals.\Question: Choose the right answer from options given a) two b) ten c) zero d) five

SOLUTION:
d