五强溪水情测报系统测报范围是什么？

A. 降低系统及电气元件的阻抗
B. 发电系统保证频率符合国家标准
C. 电力系统频率自动调整
D. 在设计选择电力供电系统及设备时，应使供电系统传输环节和耗能环节的各种设备在运行中所能承受的频率偏差符合国家标准，具备抗运行中频率扰动（偏差）的能力，保证供配电系统及电气设备经济运行

A. 革兰氏染色阳性杆菌
B. 专性厌氧菌
C. 顶端芽胞
D. 羽毛样菌落
E. 产生特异性外毒素

A. You can use aggregate functions in any clause of a SELECT statement.
B. You can use aggregate functions only in the column list of the SELECT clause and in the WHERE clause of a SELECT statement.
C. You can mix single row columns with aggregate functions in the column list of a SELECT statement by grouping on the single row columns.
D. You can pass column names, expressions, constants, or functions as parameters to an aggregate function.
E. You can use aggregate functions on a table, only by grouping the whole table as one single group.
F. You cannot group the rows of a table by more than one column while using aggregate functions.