Arrange the sentences in the correct sequence to form a coherent paragraph.

A. Their work is both unrecorded and largely unrecognised, even though in some parts of the world they handle as much as 20% of all waste.

B. Among those suffering from the global recession are millions of workers, who are not even included in the official statistics

C. In the developed countries they are the preferred ones since they recycle waste much more cheaply and efficiently than government or private corporations can.

D. These are the trash pickers, sorters and traders who extricate paper, cardboard and plastics from garbage heaps and prepare them for reuse.