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: high mountains with well-rounded peaks can be formed by collision of crustal plates. 
Sentence2: high mountains with well-rounded peaks can be formed by collision of plate tectonics.
[EX A]: collision

[EX Q]: Sentence1: healing requires rest. 
Sentence2: Healing and cell regeneration follows.
[EX A]: healing

[EX Q]: Sentence1: Sessile Attached permanently, immobile. 
Sentence2: Adult sponges are immobile.
[EX A]:
immobile