combustiblesubstance

例句：

1. 1. The gas is highly combustible and should be handled withcare.
   这种气体极易燃烧，需要小心处理。
2. 2. The fire departmentwas called to put out theflames of a nearby forest fire.
   消防部门被召来扑灭附近的森林火灾的火焰。
3. 3. The scientist discovered that somechemicals are combustible substancesthat can explode in the presence of heat.
   科学家发现某些化学物质是可燃物，在加热的情况下会爆炸。