多项选择题 Which two are true about aggregate functions? ()
单项选择题 Which /SQL*Plus feature can be used to replace values in the WHERE clause?()
单项选择题 Examine the description of the MARKS table: SUBJ1 and SUBJ2 indicate the marks obtained by a student in two subjects. Examine this SELECT statement based on the MARKS table: What is the result of the SELECT statement?()