sentence2_structure: Compounds<>containing<>the element carbon$$$Compounds containing the element carbon<>are<>the basis of all known life
sentence1: VOLATILE ORGANIC COMPOUND (VOC) is defined as any volatile compound containing the element carbon, excluding methane, carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, ammonium carbonate, and exempt compounds.
sentence2: Compounds containing the element carbon are the basis of all known life.
question: Compounds containing which element are the basis of all known life?