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: creating paper requires cutting down trees. 
Sentence2: Trees begin as epiphytes on host trees.
[A]: trees


[Q]: Sentence1: friction causes the temperature of an object to increase. 
Sentence2: pressure causes the temperature of an object to increase.
[A]: causes


[Q]: Sentence1: Marine species live mainly in shallow coastal waters. 
Sentence2: Brachiopods are strictly marine and are usually found in shallow seas.
[A]:
Marine