常见例句雙語例句There are two manufacturing methods of pyridine bases: extraction from coal tar and catalytic synthesis from ammonia, formaldehyde and acetaldehyde.吡啶堿的生産方法主要有兩種：一是從煤焦油中提取；二是從氨和甲醛、乙醛的郃成過程中獲得。 返回 acetaldehyde ammonia