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: All photos are digital images. 
Sentence2: satellites are used to take photos from space.
answer:
photos


question:
Sentence1: Cells are the units of function in living things. 
Sentence2: living things cannot survive without oxygen.
answer:
living


question:
Sentence1: a seismograph is used for measuring the size of an earthquake. 
Sentence2: A version of a simple pendulum is used to measure the size of an earthquake.
answer:

earthquake