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.

[EX Q]: Sentence1: waxy leaves are used for storing water by some plants. 
Sentence2: waxy leaves are used for water conservation by some plants.
[EX A]: leaves

[EX Q]: Sentence1: Bees feed on nectar and pollen. 
Sentence2: Plant reproduction often requires bees and nectar.
[EX A]: Bees

[EX Q]: Sentence1: Jawed fishes have thin skin. 
Sentence2: cartilaginous fish have thin skin.
[EX A]:
skin