对骨关节炎的描述下列哪项是正确的().
A.骨和关节的炎症
B.关节的化脓性炎症
C.关节的一种退行性变性病
D.非化脓性关节炎的一种
E.一种风湿性关节炎
参考答案:C
What is the candidate key of a relational database ( )
A.Fields from multiple tables that are used for sorting records
B.A set of fields in a table used to identify a record uniquely
C.A field with a constraint placed on it
D.A set of fields that have no data in them
消费者由于决策失误而对其情感受到伤害的知觉风险是()
A.功能风险
B.物质风险
C.社会风险
D.心理风险