您要查找的是不是：
- Guards patrolled the perimeter of the airfield. 卫兵沿机场四周巡逻。
- They are building a submarine cable tunnel. 他们正在建设一条海底电缆隧道。
- They are digging through the hill to make a tunnel. 他们正在凿山建一条隧道。
- The perimeter of the airfield is protected by guard-dogs. 机场外的环形防卫圈由警犬保卫着。
- The kid dug a tunnel in the sand. 小孩在沙堆里挖了一个地道。
- The barbed wire fence round the perimeter discouraged intruders. 周围有铁丝网阻止了外人闯入。
- The two lanes merge going into the tunnel. 两条车道会合后引入隧道。
- The truck cleared the tunnel safely. 卡车安全地通过了隧道。
- He has to stoop to get through the tunnel. 他得弯下腰走过地道。
- Guards had been posted at several points around the perimeter. 在环形防线上已布置了几处岗哨。
- The roar of the train reverberated in the tunnel. 火车的轰隆声在隧道里回荡。
- tunnel perimeter 隧道周边
- The prisoner escaped by digging an underground tunnel. 囚犯挖了一条地道逃跑了。
- The roof of the tunnel caved in (on the workmen). 隧道顶坍塌(压住工人).
- A fence marked the perimeter of the field. 一道篱笆标明了那块田地的周界。
- The roof of the tunnel was supported by wooden props. 坑道顶用木柱支撑。
- A tunnel dug to intercept and destroy an enemy's mine. 对抗地道截断或破坏敌人坑道而挖的地道
- The plane stalled, flipped over onto its back and crashed near the perimeter. 飞机失速了，翻了一个跟头，坠毁在机场环形围栏附近。
- How am I to find the perimeter in the dark? 我在黑暗里怎么看出周围的警戒线呢?
- Work out how long the perimeter of the playground. 请你算一算体育场的周长是多少米?
