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.

[Q]: Sentence1: folding an object causes that object to change shape. 
Sentence2: Folding an object causes that object to transform.
[A]: causes


[Q]: Sentence1: a solution is formed by one substance being dissolved in another substance. 
Sentence2: A solution is formed when limestone is dissolved in ocean water.
[A]: formed


[Q]: Sentence1: Many animals rely on sounds to communicate to others in their species. 
Sentence2: many species rely on sound.
[A]:
rely