Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.

[Q]: Tuberculosis develops in ____ stages.
[A]: two

[Q]: Humans have two lungs, each fed by ____ bronchus.
[A]: one

[Q]: Pit vipers have ____ holes, or pits, on their snouts.
[A]:
two