而且我们在他背包里发现了一把折叠刀.Andwe found a folding knife in his back pocket.那里还卖瑞士军用折叠刀,二十美元.They had a Swiss Army knife for $ 20.我花十美元买了一把非常好的折叠刀.I got a really good pocketknife for $ 10....
Carbon is needed as a reducing agent in many metallurgical operation.许多金属冶炼操作中需要碳作为还原剂.They point out inadequacies in applying criteria developed from metallurgical practice to reinforced plastics.他们指出了把冶金工业采用的断裂标准应用于增强塑...