TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Covalent bonds arise when _ atoms share electrons .

SOLUTION: two

PROBLEM: Flatworms exhibit _ forms of life styles, free-living and parasitic.

SOLUTION: two

PROBLEM: Some hygienists work for _ or more dentists.

SOLUTION:
two