<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31320050</termId><termName>natural gas</termName><termType>PT</termType><termNote><![CDATA[ Colorless highly flammable hydrocarbon gas, consisting chiefly of methane and other simple alkanes, occurring naturally in association with crude oil and used as a fuel. ]]></termNote><termCreatedDate>2026-03-30 20:26:15</termCreatedDate><relation><relationType>UF</relationType><termId>31320051</termId><termName>gas, natural</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31305907</termId><termName>fuel</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31416158</termId><termName>gas-turbine power plants</termName><termType>PT</termType></relation></term>  </Zthes>