多选题Examine the description of the STUDENTS table: STD_ID NUMBER(4) COURSE_ID VARCHAR2(10) START_DATE DATE END_DATE DATE Which two aggregate functions are valid on the START_DATE column? （ ）ASUM（start_date）BAVG（start_date）CCOUNT（start_date）DAVG（start_date，end_date）EMIN（start_date）FMAXIMUM（start_date）
多选题
Examine the description of the STUDENTS table: STD_ID NUMBER(4) COURSE_ID VARCHAR2(10) START_DATE DATE END_DATE DATE Which two aggregate functions are valid on the START_DATE column? （ ）
A
SUM（start_date）
B
AVG（start_date）
C
COUNT（start_date）
D
AVG（start_date，end_date）
E
MIN（start_date）
F
MAXIMUM（start_date）
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