Other army units are completely surrounded and cut-off from communication with their superiors.

其他部队完全被包围，与上级的联系也被切断了。

《柯林斯英汉双解大词典》

Police - This is the police. You are completely surrounded.

警察。你已经被包围了。

youdao

Muradin Bronzebeard: This looks bad. We're completely surrounded.

穆拉丁·铜须：情况看来很糟。我们被不死族包围了。

youdao

They found some of the sites under construction almost completely surrounded by water from the flooding that has followed two days of persistent rain.

BBC: Monastir is still under construction

Alliance efforts are further complicated by the logistical challenge posed by the Afghan terrain, and the fact that the pocket from which they are launching attacks on Mazar-e Sharif is completely surrounded by Taliban forces.

CNN: New attacks on Kandahar

Juniper is currently connecting an engineering lab in Sunnyvale, Calif. to the Abilene network, installing routers that are completely surrounded by monitoring equipment so they can play with their configuration and see how that affects traffic flow.

FORBES: Consortium Builds Next-Generation Net