SOX is an alternative (156) for XML. It is useful for reading and creating XML content in a (157) editor. It is then easily transformed into proper XML. SOX was created because developers can spend a great deal of time with raw XML. For many of us, the popular XML (158) have not reached a point where their tree views, tables and forms can completely substitute for the underlying (159) language. This is not surprising when one considers that developers still use a text view, albeit enhanced, for editing other languages such as Java. SOX uses (160) to represent the structure of an XML document, which eliminates the need for closing tags and a number of quoting devices. The result is surprisingly clear.
（156）是（）
A.semantic
B.pragmatics
C.syntax
D.grammar