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: Many plants respond to the days growing shorter in the fall by going dormant. 
Sentence2: Many plants respond to the autumnal equinox by going dormant.

Answer: Many


Question: Sentence1: Here, the lungs supply the blood with oxygen. 
Sentence2: Brain cells die quickly if their blood supply is cut off.

Answer: blood


Question: Sentence1: harming an animal species has a negative impact on the population size of that species. 
Sentence2: harming dogs has a negative impact on their population size.

Answer:
harming