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.
1 these impurities must be separated from the metal.
2 the liquid alloy couldn`t be distinguised from a single one-substance liquid.
3 iron will be (или will have to be) separeted from sulphur with a magnet.
4 metals may be used in the main parts of structures or machine tools.
5 metals had to be casted into varied shapes.