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]: Narwhals have ____ teeth in their upper jaw.
[A]: two


[Q]: Dholes are highly social animals and live in packs of about ____ dogs.
[A]: ten


[Q]: Scientists believe ____ out of every five breast cancers are hormone responsive.
[A]:
three