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.

Sentence1: Mollusks are invertebrates such as the common snail. 
Sentence2: Another common snail is the decollate snail.
snail

Sentence1: If the skin is painful, seek medical attention. 
Sentence2: If your skin hurts, your touch receptors will sense differences.
skin

Sentence1: Electron transport is the final stage of aerobic respiration. 
Sentence2: Long distance running, swimming, bicycling, and aerobic activity rely on endurance.

aerobic