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: Combustion generates toxic fumes. 
Sentence2: High temperatures can cause toxic fumes.

A: fumes
****
Q: Sentence1: electric devices require electrical energy to function. 
Sentence2: Lie detectors are electrical or mechanical devices.

A: devices
****
Q: Sentence1: Snail-shells and calcareous algae are often eaten for their calcium content. 
Sentence2: hermit crabs use calcium for their homes.

A:
calcium
****