单项选择题
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B.
C.
D.
多项选择题 In which four clauses can a subquery be used?（）
单项选择题 The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) Which statement finds the highest grade point average (GPA) per semester?（）
单项选择题 What is true of using group functions on columns that contain NULL values?（）
