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: Macroevolution is more than repeated rounds of microevolution. 
Sentence2: evolution over geologic time above the level of the species is more than repeated rounds of microevolution.
answer:
microevolution


question:
Sentence1: creating paper requires cutting down trees. 
Sentence2: Rainforests are destroyed by logging and all of the trees are cut down.
answer:
cutting


question:
Sentence1: blowing air into a whistle causes air to vibrate inside the whistle. 
Sentence2: blowing air into a whistle causes a sound source.
answer:

air