1. A speed limit of 30 mph was introduced in built-up areas. 在建筑物密集区域，限速为每小时30英里。
2. You must drop your speed in built-up areas. 在房屋密集区必须放慢速度。
3. The cause appears to be in part greater turbulence in the urban atmosphere as hot air rises from the built-up surface. 部分原因似乎是热空气从楼宇密集的表面上升，造成城市大气的更大湍流。
4. With much of the built-up landscape impenetrable by water, even gentle rain runs off almost immediately from rooftops, streets, and parking lots. 由于很多建筑景观都不被水穿透，即使是温和的雨水也会立刻从屋顶、街道和停车场流下。
5. The play was built up to be a masterpiece but I found it very disappointing. 那部戏被捧为杰作，可我却大失所望。
