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: threatening behavior by predators causes a porcupine to extend its quills. 
Sentence2: Fishers are one of the few specialized predators on porcupines.
answer:
predators


question:
Sentence1: Warm temperatures have helped plant growth and sizing. 
Sentence2: a greenhouse helps  plant growth.
answer:
growth


question:
Sentence1: Freeze-drying Freeze drying is a method of preserving materials. 
Sentence2: Freeze drying food keeps it viable for extended flights.
answer:

Freeze