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: Flies are insects with two wings. 
Sentence2: Flies are arthropods with two wings.
[A]: Flies


[Q]: Sentence1: Smoking accelerates the aging process. 
Sentence2: smoking accelerates the death of cells.
[A]: Smoking


[Q]: Sentence1: if an organism becomes too hot then that organism may die. 
Sentence2: if an organism overheats then that organism may die.
[A]:
die