TASK DEFINITION: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
PROBLEM: Sentence1: Many plants respond to the days growing shorter in the fall by going dormant. 
Sentence2: Many plants respond to the autumnal equinox by going dormant.

SOLUTION: Many

PROBLEM: Sentence1: boiling is when liquids are heated above their boiling point. 
Sentence2: If the pressure is reduced, the boiling point is lowered.

SOLUTION: boiling

PROBLEM: Sentence1: Invertebrates Among the invertebrates, the largest number of species are insects. 
Sentence2: insects are animals that lack a vertebral column, or backbone.

SOLUTION:
insects