The latest project is to take a city of around half a million inhabitants and discovers exactly what raw materials 62. ______ go into it and what go out. The aim is to find out how much of these raw materials could be provided whether a plant for 63. ______ recycling waste were built just outside the city. This plant would recycle not only metal such as steel, lead but copper, but also 64. ______ paper and rubber as well as. 65. ______ Another new project is being set off to discover the best 66. ______ ways of sorting and separating the rubbish. When this project is complete, the rubbish will be processing like this: first, it will 67. ______ pass through sharp metal bars which will tear open the plastic bags on which rubbish is usually packed; then it will pass through 68. ______ a powerful fan separate the lightest elements from the heavy 69. ______ solids; after that grounders and rollers break up everything what 70. ______ can be broken. Finally the rubbish will pass under magnets, which will remove the bits of iron and steel; the rubber and plastic will then sorted out in the final stage. 71. ______ The first full scale giant recycling plants are, perhaps, fifteen years away. Indeed, with the growing cost of transporting rubbish to more distance dumps, some big cities will be forced to build their own recycling plants before long.