The Canadians love the great outdoor-20% of the Canadians go camping each year-and consider the
natural phenomena of their country to be unequalled in the world. More than 90% of Canada remains
undeveloped, and the Canadians are quite content to keep it that way.
     With no lack of land, their cities tend to grow horizontally (水平地) rather than vertically (垂直地).
Just about every house in town has a large grassy lawn that requires mowing in summer and at least four
trees: two at the front and two at the back.
     In a country with that much natural space, it seems logical that one would want to look after it. Not all
the Canadians have seen the Rockies, but every single one of them wants them to be well cared for and not
buried by commercial development or tourist litter by the time they get there.
     To solve trash problems, several cities are using technology to transform household waste into soil-
enriching compost (堆肥). Edmonton has constructed North America's biggest composter. Citizens place
recyclable materials into blue bags which are picked up and taken to a sorting and treatment facility. The
$100-million plant, which covers an area the size of four football fields, processes over 1 000 tons of refuse
a day, enabling Edmonton to reuse 70% of its residential waste. Everything from glass and milk cartons (纸
盒) to metals, plastic, even concrete and asphalt (天然沥青) from sidewalk repairs are recycled.
     Another leader in recycling is the coastal city of Halifax where the recycling program has made its way
into law, making it illegal to throw an apple core into a garbage can.