The Trump administration will send a message to all US mobile phones on Thursday, as it tests an unused alert system that warns the public about national emergencies.
特朗普政府将于本周四向全美手机用户发一条信息，用以测试还未投入使用的紧急警报系统。
Phones will make a loud tone and have a special vibration according to the Federal Emergency Management Agency (FEMA), which will send the alert.
据联邦紧急事务管理署称，警报发出时，手机会发出巨大的声音并会伴有一种特殊的震动。
The test message will be headlined “Presidential Alert” and will go on to read “THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed.”
这一信息将以“总统级警报”命名，信息的内容为“这只是一条来自国家无线警报系统的测试信息，无需采取任何行动.”
US mobile phone users will not be able to opt out of the test.
所有移动手机用户都必须接受此项测试。
Former US president Barack Obama signed a law in 2016 which required FEMA to design a system where the president could send mobile phone alerts in national emergencies.
美国前总统奥巴马于2016年签署一项法令，要求联邦紧急事务管理署设计一套系统，以便总统可以向全民发送紧急事件的警报。
The president has responsibility for deciding when the nationwide alerts are used.
总统有权决定何时发布警报。
FEMA has issued more than 36,000 mobile phone alerts since launching a wireless emergency system in 2017.
自2017年以来，联邦紧急事务管理局已经向超过3000部手机发出过该无线警报。
The messages have varied from alerts about natural disasters and extreme weather to notifications about missing children.
据悉，这些信息的内容包罗万象，十分多样，大到自然灾害、极端天气，小到儿童失踪都包括在内。