97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区 狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項選擇題

Radiation can spread a fire by ().

A.transmitting the heat of a fire through the ship s metal
B.burning liquids flowing into another space
C.heated gases flowing through ventilation systems
D.the transfer of heat across an unobstructed space

微信掃碼免費搜題