instruction:
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.
question:
Sentence1: a sifter is used for separating mixtures. 
Sentence2: a sifter is used for some recipes.
answer:
sifter


question:
Sentence1: the uterus is used in reproduction. 
Sentence2: Reproduction uses the same organ as menstruation.
answer:
reproduction


question:
Sentence1: All electrons contain energy. 
Sentence2: plasma is formed using energy.
answer:

energy