What percentage of Canada's municipal solid waste is buried in landfills? 

A)  about 15% 
B)  about 20% 
C)  about 50% 
D)  about 75%

____________________ is diminished by extinction.

What process can enrich a copper deposit, perhaps making it profitable?

A) intense fracturing associated with meteoroid impacts, like at Sudbury
B) deposition of large amounts of quartz and calcite in the rock
C) dispersing the copper-rich grains by wind and water
D) leaching by weathering and redeposition at the water table