Web services within a single domain, like hotel reservation services, should have at least an industrial agreement and standard to specify the required input variables and the possible outputformat.
VoiceXML is the name given to the standard for voice-based XML output, although the file format itself is called VXML.
VoiceXML 一名源于一种标准，用于基于语音的 XML 输出，但是这种文件格式本身称为 VXML。
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Writes the text representation of the specified objects, followed by the current line terminator, to the standardoutput stream using the specified format information.