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: mountains are formed by earthquakes. 
Sentence2: Mountains are formed by moving plates.
answer:
are


question:
Sentence1: a greenhouse is used to protect plants by keeping them warm. 
Sentence2: Flower size varies by plant.
answer:
plants


question:
Sentence1: Food is easier to chew because it is moistened by saliva from the salivary glands. 
Sentence2: Brain food Bagels are brain food.
answer:

Food