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: friction causes the temperature of an object to increase. 
Sentence2: pressure causes the temperature of an object to increase.
[EX A]: causes

[EX Q]: Sentence1: healing requires rest. 
Sentence2: Healing and cell regeneration follows.
[EX A]: healing

[EX Q]: Sentence1: volcanic ash in the atmosphere decreases the temperature by blocking the sun. 
Sentence2: Volcanic ash can slow plant growth.
[EX A]:
ash