sewer

• Do not allow chemicals to creep into the sewer grid
  不允许把化学品蔓延到下水道的分格中。
• Trenchless construction and testing of drains and sewers
  排水管和污水管的非挖沟施工和试验
• I went straight in through the sewer controls
  我直接从排水系统进去的
• Concrete and reinforced concrete sewer pipes
  混凝土和钢筋混凝土排水管
• I went straight in through the sewer controls
  我直接从排水系统进去的
• A seamstress and a sewer fell down into a sewer line
  一位女裁缝和一位缝纫师掉进了下水沟。
• A total of78 ditches were filled in and sewers were laid
  一共填了78条沟，并敷设了下水道。
• Trenchless construction and testing of drains and sewers
  非挖沟结构和雨水及污水排放管试验
• The first 1 ) sewers appeared in rome around 700 b . c
  下水道则最早出现于西元前七百年的罗马。