Which statement best describes immigration in Canada? 

A)  it remains a crucial factor in population growth 
B)  it is mainly from Africa and Europe 
C)  it is directed towards our rural areas 
D)  it will stabilize the population at about 500 million by the end of the century

Upon what basis were the upper and lower boundaries of the Mesozoic Era defined?

A) dramatic changes in the color of the rocks from green to tan
B) major episodes of mountain building
C) abrupt changes in the types of fossils, representing mass extinctions
D) the discovery that a meteoroid impact may have killed the dinosaurs