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: Tin exists in ____ allotropic forms.

A: three
****
Q: Seismologists offer ____ major theories for the occurrence of large, deep earthquakes.

A: three
****
Q: Dinoflagellates are unicellular forms with one to ____ flagellae .

A:
three
****