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: the emission of sulfur dioxide causes acid rain. 
Sentence2: the emission of sulfur dioxide causes soil weathering.
causes

Sentence1: being burried under soil and mud changes peat into coal through extreme heat and pressure in a swamp over a long period of time. 
Sentence2: Marble is used for sculptures, and coal is used for fuel and energy like light.
coal

Sentence1: White eye color is a recessive trait. 
Sentence2: crossing two living things with white eyes causes their offspring to have white eyes.

White