常見(jiàn)例句雙語(yǔ)例句There are two manufacturing methods of pyridine bases: extraction from coal tar and catalytic synthesis from ammonia, formaldehyde and acetaldehyde.吡啶堿的生產(chǎn)方法主要有兩種：一是從煤焦油中提取；二是從氨和甲醛、乙醛的合成過(guò)程中獲得。 返回 acetaldehyde ammonia