八面体    octahedron?

目镜    ocular?

拉辉煌斑岩    odinite?

里程表    odometer?

着嗅剂    odorant?

气味    odour?

内业    office operation?

官方地图制图    official cartography?

官方地图    official map?

胶印机    offset machine?

胶版印刷    offset printing?

近岸沙洲    offshore bar?

离岸流    offshore current?

滨外的    offshore?

定居    oikesis?

含油盆地    oil basin?

油母岩    oil bearing rock?

石油矿床    oil deposit?

油田水    oil field water?

油田    oil field?

油气    oil gas?

石油地质学    oil geology?

含油层    oil horizon?

油料罪    oil plant?

油藏    oil pool?

油砂    oil sand?

油苗    oil seepage?

油页岩    oil shale?

油膜    oil slick?

油井    oil well?

老年山    old mountains?

古老红色砂岩    old red sandstone?

老年期    old stage?

老年谷    old valley?

嗅觉    olfaction?

渐新世    oligocene?

奥长石    oligoclase?

微毒酌    oligodynamic action?

贫瘠棕色土    oligotrophic brown soil?

贫瘠条件    oligotrophic conditions?

寡养湖    oligotrophic lake?

寡养沼泽    oligotrophic moor?