墨西哥城现在向手机发送地震警报

smartphone(s) – n. a mobile telephone that can be used to send and receive e-mail, connect to the Internet, and take photographs

magnitude – n. a number that shows the power of an earthquake

vibrate – v. to move back and forth or from side to side with very short, quick movements

context – n. the situation in which something happens

loudspeaker(s) – n. a device that is used to make sound, such as music or a person's voice, louder and to send it out so that many people can hear it in a public space

ringtone(s) – n. the sound that a cell phone makes when someone is calling