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: 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: Moisture is required for the microorganisms to grow. 
Sentence2: Moisture can cause infections to grow.
[EX A]: Moisture

[EX Q]: Sentence1: Marine species live mainly in shallow coastal waters. 
Sentence2: Marine Science Marine science is the study of the sea.
[EX A]:
Marine