Producers obtain and make products to sell.
Transporters distribute the products to the shops.
Sales people sell the products or services to the
consumers.
Consumers buy the finished product.
Occupations:
http://www.educa2.madrid.org/binary/703/files867/
Types of trade:
http://www.primaria.librosvivos.net/archivosCMS/3/3/16/usuarios/103294/9/ud14_4EP_Science_tiposcomercio_1/frame_prim.swf
Work and professions:
