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: Heterotrophs are living things that cannot make their own food. 
Sentence2: food contains organic molecules.
answer:
food


question:
Sentence1: Caverns Secrets are hidden in caves. 
Sentence2: hidden caves are formed by carbonic acid in groundwater seeping through rock and dissolving limestone.
answer:
are


question:
Sentence1: if a planet becomes too hot then that planet cannot sustain life. 
Sentence2: If a planet is too close to a star, then it will be too hot for liquid water to exist.
answer:

hot