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: Herbs are medicines and aids. 
Sentence2: herbs are used for curing people when they are sick.
[A]: Herbs


[Q]: Sentence1: evaporation can be used for separating a solute from a solvent in a solution. 
Sentence2: Evaporation can be used for segregation a solute from a solvent in a solution.
[A]: a


[Q]: Sentence1: Bacteria are the most diverse and abundant group of organisms on Earth. 
Sentence2: Bacteria are the most diverse and abundant group of life form on Earth.
[A]:
Bacteria