How many minutes before the train conductor leaves, remind the part-time announcer to broadcast the safety precautions and remind the station passengers?

In order to reflect the high-level EMU broadcasting, broadcasters must have strict qualifications and obtain the certificate of Putonghua proficiency test from the national or local language committee. 2. The announcer must broadcast in standard Mandarin, with standard pronunciation, clear articulation, friendly tone, moderate speech speed and rich feelings. Trains running within 3.3 hours generally only broadcast welcome speech, service equipment introduction, safety tips, station names and background music. Trains running for more than 3 hours can appropriately increase the broadcast content without disturbing passengers' rest. Sleeper EMU stops broadcasting after 20 minutes; The train starts at 6: 45 am on April 1 Sunday to1October 3 1 Sunday and at 7: 00 am on June1Sunday to March 3 1 Sunday every year. 4. The contents played by the train passenger information service and audio-visual playback system are provided by the passenger transport department and entered by the vehicle department. Record the common broadcast content of EMU, and the CRH 1 broadcast content data shall be uploaded to the passenger information system of EMU. 5. In case of temporary parking, delay, equipment failure and other emergencies, the EMU shall immediately broadcast the emergency plan and publicize it through live broadcast. Temporary drafts that need to be broadcast live can only be broadcast after being examined and approved by the train conductor. 6. Establish the daily management files of broadcasters, and record and record the daily broadcast quality, advantages and disadvantages of broadcasters as the basis for broadcasters to take up their posts.