设在某SELECT语句的WHERE子句中，需要对Grade列的空值进行处理。下列关于空值的操作中，错误的是（） A: A.Grade IS not null B: B.Grade IS null C: C.Grade = null D: D.Not(Grade IS null)

Which grade were they in? A: Grade 8 B: Grade 9 C: Grade 10 D: Grade 11

What grade is the woman in A: Grade one. B: Grade two. C: Grade three.

The most common division between primary and secondary education in the US is ___________.（ ） A: primary schools (Grade 1 to Grade 6) and middle schools (Grade 7 to Grade 12) B: elementary schools (Grade Kindergarten to Grade 8) and high schools (Grade 9 to Grade 12) C: elementary schools (Grade Kindergarten to Grade 3), middle schools (Grade 4 to Grade 6) and high schools (Grade 7 to Grade 12) D: grammar schools (Grade Kindergarten to Grade 6) and high schools (Grade 7 to Grade 12)

They are the students of ______. A: grade 7 B: Grade 7 C: 7th grade D: Grade 7th

【单选题】5. 假定student表中有字段grade,grade代表分数,依次统计grade字段的最大值,最小值,平均值的SQL语句是 A. SELECT max(grade),min(grade),average(grade) FROM student; B. SELECT max(grade),min(grade),avg(grade) FROM student; C. SELECT min(grade),average(grade),max(grade) FROM student; D. SELECT min(grade),avg(grade),max(grade) FROM student;

查询统计选课表SC中成绩列Grade的最小值，可以用_______函数。 A: Min(Grade) B: Max(Grade) C: Avg(Grade) D: Sum(Grade)

查询统计选课表SC中成绩列Grade的平均值，可以用_______函数。 A: Sum(Grade) B: Avg(Grade) C: Min(Grade) D: Max(Grade)

全世界规定辐射剂量标准（）。 A: 低于10千/Grade B: 低于12千/Grade C: 低于15千/Grade D: 低于20千/Grade

Jim is in _____. A: Class one grade six B: grade one class six C: Class One Grade Six D: Grade One, Class six