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]: Many biologists believe the sandhill has been virtually unchanged for ____ million years.
[EX A]: nine

[EX Q]: All crabs have ____ pair of chelipeds and four pairs of walking legs .
[EX A]: one

[EX Q]: Many tractors have ____ wheel drive to get extra grip on the hills and in wet conditions.
[EX A]:
four