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: a sifter is used for separating mixtures. 
Sentence2: a sifter is used for some recipes.
[A]: sifter


[Q]: Sentence1: an animal requires nutrients to grow and heal. 
Sentence2: Microbes can help an animal to grow and heal.
[A]: grow


[Q]: Sentence1: Life is reduced to survival . 
Sentence2: Better senses have a positive impact on an animal's life.
[A]:
Life