CONVENTION
（打电话时的招呼语）喂
You say 'Hello' to someone at the beginning of a telephone conversation, either when you answer the phone or before you give your name or say why you are phoning.
例句
A moment later, Cohen picked up the phone. 'Hello?'
过了一会儿，科恩接起电话。“喂？”
Hallo, may I speak to Frank, please.
喂，我找弗兰克。