Из активного залога сделать пассивный…

Из активного залога сделать пассивный 1. We must separate these impurities from the metal. 2. We could not distinguish the liquid alloy from a single one-substance liquid. 3. They will have to separate iron from sulphur with a magnet. 4. We may use metals in the main parts of structures or machine tools. 5. They had to cast metals into varied shapes.