Once france was prostrate, he must if possible conquer or destroy great britain . 法国一经投降，只要可能，他就必然要征服或毁灭大不列颠。
Conversion of ferrous to ferric iron occurs readily upon aeration at ph 7. 0-7. 5 . 在PH值7075时，一经曝气亚铁离子很容易转化为铁离子。
Once the desired specific gravity is established, the same strength must be used henceforth . 所需的比重一经确定，以后就必须使用同一浓度的酸。
Once the size of the expedition had been determined, it was possible to go ahead with intensive training . 远征部队的规模一经确定，就立即可以进行严格的训练。
When he had once begun to think about this he did not stop until he had reasoned it all out . 一经开始思索这个问题，他就不肯罢休，一直到他把道理完全想出来为止。
This decision, once reached, would be the guiding principle of the war until germany was defeated . 此项决心一经确定，直须至击溃德军为止，始终作为战争的指导原则。
Since the guides are usually made from materials having high-energy surfaces, wetting by polar lubricants usually is satisfactory . 由于导纱杆一般都是用具有高能表面的材料制备，一经极性润滑剂润滑，往往即达到饱和状态。
What seems venerable by an accumulation of changes is reduced to familiarity when we come seriously to consider it solely in connection with time . 凡是由于变革万千而看来似乎是古老久远的时代，一经从时间方面认真地考虑，就会变得切近了。
5 . there will be no refunds payable on any tickets 所有门票一经售出，不得退票。
The flue should draw better once it ' s been swept 烟道一经清扫，通风情况应好些。
