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.

[EX Q]: Most newborns nurse every one to ____ hours, even at night.
[EX A]: three

[EX Q]: All grays have ____ saturation.
[EX A]: zero

[EX Q]: Fluorescent lighting is about ____ times as efficient as incandescent lighting.
[EX A]:
four