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: Combustion-related, motor vehicles, wood burning, open burning, industrial processes. 
Sentence2: Combustion is used to produce heat.
[EX A]: Combustion-related

[EX Q]: Sentence1: Tree-ring dating the 1700 Cascadia earthquake. 
Sentence2: estimating the age of trees can be used in reviewing earthquake history.
[EX A]: earthquake

[EX Q]: Sentence1: Human population growth has resulted in habitat destruction, causing massive extinctions. 
Sentence2: human population growth causes animals to find shelter in another habitat.
[EX A]:
Human