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: wind is used for producing electricity. 
Sentence2: Wind is caused because of pressure differences in the atmosphere.
answer:
wind


question:
Sentence1: the force of water against the seed coat causes a root to emerge from a seed. 
Sentence2: Germination depends on the seed coat.
answer:
coat


question:
Sentence1: Leeches are external parasites. 
Sentence2: Leeches live on the surface of their hosts.
answer:

Leeches