单项选择题
A．began to operate fifteen years ago B．will probably take less than fifteen years to build C．will be built fifteen years later D．will probably be in operation in fifteen years
A．Breaking up what is breakable. B．Sharpening metal bars. C．Separating light elements from the heavy ones. D．Sorting out small pieces of metal.
A．a cheap way to get energy B．the location of recycling plants C．new ways of recycling waste D．the word rubbish could lose its meaning