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: healing requires rest. 
Sentence2: Healing and cell regeneration follows.
[EX A]: healing

[EX Q]: Sentence1: June Summer Triangle Three bright stars light up the summer sky. 
Sentence2: Nuclear reactions in stars cause them to brighten up the summer sky.
[EX A]: bright

[EX Q]: Sentence1: Rapid growth means rapid advancement. 
Sentence2: Infancy is the period of most rapid advancement.
[EX A]:
advancement