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: Interest in fossils is worldwide. 
Sentence2: paleontologists study something with worldwide interest.
[A]: Interest


[Q]: Sentence1: People of all ages and activity levels perspire or sweat. 
Sentence2: Perspiration reduces body heat.
[A]: perspire


[Q]: Sentence1: microscope is used to see small things by biologists by making them appear bigger. 
Sentence2: Biologists study small things that can't normally be seen with an unaided eye.
[A]:
small