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.

Q: Sentence1: All frogs are amphibians. 
Sentence2: frogs have permeable skin that easily absorbs substances from the environment.

A: frogs
****
Q: Sentence1: nectar is used for attracting pollinators by plants. 
Sentence2: butterflies pollinate plants.

A: plants
****
Q: Sentence1: plant requires seed dispersal for reproduction. 
Sentence2: plants are pollinated by birds.

A:
plant
****