TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Special relativity shows that time behaves surprisingly like the _ spatial dimensions.

SOLUTION: three

PROBLEM: Mitosis consists of _ stages.

SOLUTION: four

PROBLEM: Elephants have _ molars, which are replaced five times, for a total of six sets in a lifetime.

SOLUTION:
four