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: Friction causes the temperature of a toy to increase.
[EX A]: causes

[EX Q]: Sentence1: a thermometer is used to measure temperature. 
Sentence2: a thermometer is used to measure heat.
[EX A]: a

[EX Q]: Sentence1: boulders are formed by glaciers melting sometimes. 
Sentence2: Water expands as it is heated, and glaciers melt.
[EX A]:
glaciers