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: gills are used for breathing water by aquatic animals.
Sentence2: gills are used for breathing water by sharks.
answer:
are

question:
Sentence1: Acid rain is precipitation which pH is 5.7 or lower.
Sentence2: gases from burning coal causes precipitation which pH is 5.7 or lower.
answer:
5

question:
Sentence1: Acids turn blue litmus paper red and have a sour taste.
Sentence2: Sour tasting things changes litmus paper from blue to red.
answer:
sour