Nobody would stand out admitting the fact, for some reason,      they lost the game.

A．that

B．which

C．what

D．why

下列物质在空气中燃烧时，用干燥的烧杯罩在火焰上方，烧杯内壁没有水珠出现的是（　　）

A．一氧化碳燃烧

B．氢气燃烧

C．蜡烛燃烧

D．甲烷燃烧