TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Some bird feeders have _ perches at all, but neither do tree trunks.

SOLUTION: no

PROBLEM: Ozone is a form of oxygen in which the molecule contains _ atoms instead of two.

SOLUTION: three

PROBLEM: Port is Portugal's best known wine, it represents about _ percent of the wine production.

SOLUTION:
six