问题
单项选择题
Where can you see from the air the migration of the mammals
A．In the Pribilot Islands.
B．In the Bering Sea.
C．In southern California.
D．In northern Canada.
答案
参考答案：D
解析：[分析] 细节题型。 见第三句、五句：An example is the caribou，reindeer that graze on the grassy slopes of northern Canada．．．Their tracks are so well-worn that they are clearly visible from the air．因此答案为D。