单选题 16.  Slavery was ______ in Canada in 1833, and Canadian authorities encouraged the slaves, who escaped from America, to settle on its vast virgin land.
【正确答案】 C
【答案解析】 1833年，加拿大废除了奴隶制，当局鼓励从美国逃跑的奴隶在其广袤的处女地上定居。