绝缘材料按极限温度可划分为哪几个等级?各等级的极限温度分别是多少?
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观花类、观叶类、观果类、观茎类、观芽类等是按花卉的性质进行分类的。
A. 正确
B. 错误
A user utilizing an alias to update a subset of columns in a table must have UPDATE privileges on which of the following DB2 objects?()
A. Table
B. Columns
C. Table and Alias
D. Columns and Alia