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.

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

Example Input: Sentence1: Warm temperatures have helped plant growth and sizing. 
Sentence2: a greenhouse helps  plant growth.
Example Output: growth

Example Input: Sentence1: Reptile parents provide little if any care to their young. 
Sentence2: Alligator and crocodile parents provide little care to their young.
Example Output:
care