In the city, some of the following seemingly harmless places may easily become drug trading sites: 1. **Old residential buildings**: The flow of people is relatively complex, and the entry and exit of outsiders is not easy to attract special attention. In addition, some old buildings are loosely managed, which is convenient for trading. 2. **Abandoned factories or warehouses**: The location is remote, the space is large and hidden, which is convenient for hiding drugs and conducting trading activities. 3. **Entertainment venues such as KTV, bars, nightclubs, etc.**: The crowds are dense and the environment is noisy, and the identities of the people are diverse. Under the background of dim lights and music, the transactions are easy to conceal. 4. **Some hidden alleys or hutongs**: There are fewer pedestrians, which is convenient for escaping after a quick transaction, and the surrounding environment is not conducive to the police's rapid detection and control. 5. **Small hotels near long-distance bus stations and railway stations**: The flow of people is large, and the parties to the transaction can easily use the excuse of accommodation to conduct drug transactions here. 6. **Rental houses in the urban-rural junction on the edge of the city**: The tenant composition is complex, and the landlords are not in place. It is easy to become a hotbed for drug transactions.