环形防线的英文

• perimeter

• 环形:    annular; ringlike; ring form ...
• 防线:    line of defense
• 环形防冰管:    circumferential anti-icing tube
• 环形防护屏:    ring shaped shield; ring-shaped shield
• 环形防空:    circular air defense

例句与用法

1. Guards had been posted at several points around the perimeter
   在环形防线上已布置了几处岗哨
2. Guards have been posted at several point around the perimeter
   在环形防线上已布置了几处岗哨。

其他语言

环形防线的法语：périmètre
环形防线的俄语：внешняя граница
环形防线的阿拉伯语：محيط;