Wood, the primary source of heat for homes and industries and also used in the iron industry as processed charcoal, was diminishing in supply.
木材是家庭和工业的主要热源，也以加工木炭的形式用于铁工业，它的正在减少。
2
A fire requires fuel to burn, air to supply oxygen, and a heatsource to bring the fuel up to ignition temperature.
一把火需要燃料来燃烧、空气来提供氧气还有使燃料到底燃烧温度的热量。
3
The technicality and economy of heatsource scheme of district heat-supply are analyzed and compared with a practical heat-supply scheme by economical analysis methods.