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.

Sentence1: healing requires rest. 
Sentence2: Healing and cell regeneration follows.
healing

Sentence1: Genetics is the study of inheritance. 
Sentence2: Pedigrees are useful tools for studying genetics.
Genetics

Sentence1: hitting an object causes the particles in that object to vibrate. 
Sentence2: Hitting an object causes the particles in it to accelerate.

causes