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]: Smoking causes lung cancer in ____ ways.
[A]: two


[Q]: Most programmable circuits have at least ____ channels.
[A]: two


[Q]: Flea larvae metamorphose through ____ stages before spinning a cocoon and entering the pupal stage .
[A]:
four