TASK DEFINITION: Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.
PROBLEM: Light drives the interconversion of ____ forms of phytochroms.

SOLUTION: two

PROBLEM: Viceroys produce ____ generations per year, and the food habits of each generation differs.

SOLUTION: three

PROBLEM: Red algae are haplo-diplonts with a complicated life cycle that often involves ____ phases.

SOLUTION:
three