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.
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Question: Sentence1: Sound vibrations travel at different speeds through different materials. 
Sentence2: the type of material through which sound passes changes the sound vibrations.

Answer: Sound


Question: Sentence1: Methane gas is a produced by rotting compost, trash, and human waste. 
Sentence2: Methane gas can be produced by Slime molds.

Answer: Methane


Question: Sentence1: chemical weathering causes iron in rock to oxidize. 
Sentence2: Also pyrite within the altered wall rock is oxidized to limonite, geothite and hematite.

Answer:
oxidize