问题：
[不定项选择题] Campaigning on the Indian frontier is an experience by itself.Neither the landscape nor the people find their counterpartsin any other portion of the globe.Valley walls rise steeply five or six thousa
A、Melting snows.
B、Large population.
C、Steep hillsides.
D、Fertile valleys.
参考答案：
B、Large population.
● 参考解析
