TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Black women giving birth have a four to _ higher rate of mortality than white women do.

SOLUTION: one

PROBLEM: Ozone leaves _ by-products except pure oxygen.

SOLUTION: no

PROBLEM: Batteries contain hydrogen and oxygen, _ flammable and explosive gasses.

SOLUTION:
two