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: erosion of soil has a negative impact on the environment. 
Sentence2: erosion of soil has a negative impact on forests.
answer:
erosion


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


question:
Sentence1: Flatworms belong to the phylum Platyhelminthes. 
Sentence2: Phylum Platyhelminthes are mostly parasitic.
answer:

Platyhelminthes