below ground

They built a bomb shelter below ground.

他下修建了一个防空洞。

Their missile silos are below ground.

他的导弹发射井下。

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

下面，起假根的用的茎具非常退化叶片，有或没有块茎或根状茎。