TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: New species are believed to arrive in the Mediterranean at the rate of _ to five annually.

SOLUTION: four

PROBLEM: Full sun is classified as any area that receives a minimum of _ hours of direct sunlight each day.

SOLUTION: six

PROBLEM: Plant bulbs deeper than seed, usually _ to four times the diameter of the bulb.

SOLUTION:
three