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: Generally, pheromones are volatile substances. 
Sentence2: Male dogs use volatile substances in urine to mark their territory.
answer:
substances


question:
Sentence1: Cultivation is easier if soil is loose. 
Sentence2: soil with more oxygen is easier to cultivate.
answer:
Cultivation


question:
Sentence1: creating paper requires cutting down trees. 
Sentence2: Pulped wood is used to make paper.
answer:

creating