已知有关系“STUDENT”，则关系运算σANE＜80(STUDENT)用SQL语句表示为 (52) 。 A: SELECT( * )FROM STUDENT WHERE AVE ＜ 80 B: SELECT( * ) FROM STUDENT HAVING AVE ＜ 80 C: SELECT(AVE) FROM STUDENT WHERE AVE ＜ 80 D: SELECT(AVE） FROM STUDENT HAVING AVE ＜ 80

​下列SQL语句中，_____________可以在“学生-课程”数据库正确实现“查询选修并成绩良好3门以上课程的学生学号及其满足条件的课程门数”。‌ A: SELECT Sno，COUNT(*)FROM SCGROUP BY SnoHAVING Grade>=80 AND COUNT(*) >3 B: SELECT Sno，COUNT(*)FROM SCWHERE Grade>=80GROUP BY SnoHAVING COUNT(*) >3 C: SELECT Sno，COUNT(*)FROM SCGROUP BY SnoWHERE Grade>=80HAVING COUNT(*) >3 D: SELECT Sno，COUNT(*)FROM SCGROUP BY SnoWHERE Grade>=80 AND HAVING COUNT(*) >3

例如数据库中有A表,包括学生、学科、成绩三个字段,数据库结构为:[br][/br] [br][/br] 学生 学科 成绩 [br][/br] 张三 语文 60 [br][/br] 张三 数学 100 [br][/br] 李四 语文 70 [br][/br] 李四 数学 80 [br][/br] 李四 英语 80 [br][/br] 张三 语文 60 [br][/br]如何统计最高分>80的学科?( ) A: SELECT MAX(成绩) FROM A GROUP BY 学科 HAVING MAX(成绩)>80; B: SELECT 学科 FROM A GROUP BY 学科 HAVING 成绩>80; C: SELECT 学科 FROM A GROUP BY 学科 HAVING MAX(成绩)>80; D: SELECT 学科 FROM A GROUP BY 学科 WHERE MAX(成绩)>80;

We confirm having a_____(接受） your order for 5M/T dried chilies, New Corp, at $80 CIF London for May s_____(装运）.

The Greens _______ lunch when I got to their house . A: were having B: was having C: are having D: is having

Actually, we ________________ lunch. A: are just having B: just are having C: are having just D: just having

My family ______ supper when he came. A: was having B: were having C: is having D: are having

What seems to keep people healthy? A: Having money. B: Having friends C: Having hobbies D: Having only one spouse.

I'm sorry I didn't know you ________ a<br/>meeting just now. A: are having B: having C: were having D: was having

The author mentions all of the following advantages of publicity EXCEPT ______. A: having no time costs B: having attentiveness C: having high credibility D: having high profitability