TASK DEFINITION: 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.
PROBLEM: Pyrimidines contain ____ ring and purines contain two rings.

SOLUTION: one

PROBLEM: Lightning is ____ times hotter than the surface of the sun.

SOLUTION: three

PROBLEM: Formal rush is a set of ____ parties held during the third week of the fall semester.

SOLUTION:
four