They built a bomb shelter below ground.

在地下修建了一个防空洞。

Their missile silos are below ground.

导弹发射井在地下。

Stem with much reduced leaf blades that function as rhizoids below ground, with or without tubers or rhizomes.

在地下面，起假用茎具非常退化叶片，有没有块茎茎。