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: An accounting period is simply a period of time. 
Sentence2: seconds are used to measure a period.

SOLUTION: period

PROBLEM: Sentence1: Some birds are pollinators that co-evolved with plants. 
Sentence2: insects pollinate plants.

SOLUTION: plants

PROBLEM: Sentence1: habitat destruction causes animals to move to find shelter in another habitat. 
Sentence2: Aquarium habitat is very different from ocean habitat.

SOLUTION:
habitat