这名重量级拳击冠军将尝试挑战霍利菲尔德的世界冠军头衔。The heavyweight champion will be given a shot at Holyfield's world title.我正想换工作，想尝试点不一样的事情来挑战一下自己。I'm trying to move on and stretch myself with something different.幸福的秘诀就是要不停地给自己设定新的挑...
The factory produces propellant for ballistic missiles.这个工厂为弹道导弹生产推进剂。Some stratification exists in the spray produced by any liquid propellant injector.由任何液体推进剂喷注器所产生的喷雾都存在某些成层现象.The nitroguanidine is added to the prope...