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: Flies are insects with two wings. 
Sentence2: Flies are arthropods with two wings.
answer:
Flies


question:
Sentence1: Streams may start with runoff or water seeping out of a spring. 
Sentence2: Most water comes from precipitation.
answer:
water


question:
Sentence1: Viral infection means there is a virus living in the body. 
Sentence2: Some viral infections live in a dormant state.
answer:

Viral