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.

[EX Q]: Sentence1: a thermometer is used to measure temperature. 
Sentence2: a thermometer is used to measure heat.
[EX A]: a

[EX Q]: Sentence1: if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past. 
Sentence2: Fossils are the remains of prehistoric life.
[EX A]: fossils

[EX Q]: Sentence1: Spicules, amoeboid cells, and collar cells are characteristic of sea anemones. 
Sentence2: Sponges and sea anemones have similar types of specialized cells.
[EX A]:
anemones