(2013·江西南昌一模)As ______ mountains surrounding our village are turning much greener, they have become ________ home to a large number of wild animals.

A．the; /

B．the; a

C．/; a

D．the; the

三角形的面积一定，底与高成______比例关系．圆锥的底面积一定，体积与高成______比例关系．