TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Many comets have _ tails.

SOLUTION: two

PROBLEM: White sturgeon inhabit _ large river systems, all on the western coast of North America.

SOLUTION: three

PROBLEM: Malignant cases have _ characteristic stages of infection, remission and intoxication.

SOLUTION:
three