单项选择题

在SQL语句中,与表达式sno NOT IN("s1","s2")功能相同的表达式是______。 A.
sno="s1" AND sno="s2" B.
sno="s1" OR sno="s2" C.
sno!="s1" AND sno!="s2" D.
sno!="s1" OR sno!="s2"

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