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: Malaria kills up to ____ million people each year.

SOLUTION: two

PROBLEM: Carbon atoms are tetravalent, and therefore, can have ____ bonding pairs around each carbon atom.

SOLUTION: four

PROBLEM: Taproots can grow an inch per day and eventually reach ____ feet in length.

SOLUTION:
four