单项选择题
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
A. have completed what was started B. have gotten ready to start C. have achieved a great deal toward D. have put an end to