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


[Q]: Sentence1: Parasites are organisms that live off a host. 
Sentence2: roundworms may be free-living or live off a host.
[A]: host


[Q]: Sentence1: Arthropods Arthropods have jointed segmented exoskeletons. 
Sentence2: Insects have jointed segmented exoskeletons.
[A]:
exoskeletons