这两个国家交界于山脉。
zhè liǎng gè guójiā jiāojiè yú shānmài 。
These two countries have a common border at the mountains.
湖泊和沼泽交界。
húpō hé zhǎozé jiāojiè 。
The lake and the swamp have a common border.
这个地区的森林和草原交界。
zhègè dìqū de sēnlín hé cǎoyuán jiāojiè 。
The forests and grasslands in this area have a common border.