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- difficult flotation ores 难选矿石
- Based on the measurement the deinking efficiency after flotation or washing can be calculated，and the efficiency of the equipment and technology can be estimated. 通过测出的浓度可以计算油墨粒子通过浮选或洗涤的分离效率，并用来评定浮选和洗涤设备及其工艺的效果。
- In a difficult or embarrassing position. 处于困境处于一种困难或尴尬的境地
- Whether it rains or not makes no difference to me. 下不下雨对我来说都一样。
- Difficult to fathom or understand; impenetrable. 不可思议的难于测量或理解的; 费解的
- Difficult to comprehend or see; illegible. 难以理解的难以理解或看清的; 难认的
- It must be difficult to play various personae in the same movie. 在同一个电影中扮演不同的角色肯定不容易。
- Navigation is difficult on this river because of the hidden rocks. 因为河上有暗礁，所以在这条河上航行很困难。
- It was difficult to tell his exact age. 很难判断他到底多大岁数。
- Many one or little one is indifferent to me. 多一个或少一个对我是无关紧要的。
- Chock the barrel up or else it will roll over. 用楔子塞住圆桶,不然它会滚过去。
- It is difficult to express it in terms of science. 要用科学的字眼来表达它是很困难的。
- Flotation or swimming aids for the physically challenged 身体不便者用游泳辅助工具
- It was difficult to gauge how people would respond. 大家的反应如何难以估计。
- Do you teach your students singly or in groups? 你教学生是个别地教还是按组教？
- She handled a difficult argument skilfully. 她巧妙地应付了一场艰难的辩论。
- Do you prefer to have rice or buns? 你愿意吃饭还是吃馒头。
- Most synthetic detergents are in the form of powder or liquid. 大多数合成洗涤剂呈粉状或液态。
- Fill your radiator with water, or your engine will overheat. 给你的散热器充水，否则引擎会过热。
- He find it difficult to give shape to his idea. 他觉得很难把他的想法，明确表达出来。
