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: Rabbits have ____ incisors in the upper jaw where rodents have only two.

A: four
****
Q: Comprehension is the second of the ____ elements of the informed consent process.

A: three
****
Q: Sewage travels through ____ different sets of pipes.

A:
three
****