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: conserving water can be used for survival in a dry environment. 
Sentence2: conserving water can be used for survival in deserts.
conserving

Sentence1: Combustion generates toxic fumes. 
Sentence2: High temperatures can cause toxic fumes.
fumes

Sentence1: a light bulb is used for seeing in the dark. 
Sentence2: light is required for seeing.

seeing