runway sweeping

例句：

1. 1. The pilots must ensure therunway is clear before takeoff.
   飞行员必须确保起飞前跑道是干净的。
2. 2. Themaintenance crew was busy sweeping the runway after a heavy rain.
   维修人员在大雨后忙着清扫跑道。
3. 3. Theairport authorities are conductinga thorough inspection of the runway to prevent accidents.
   机场当局正在彻底检查跑道，以防止事故。