3、计算平均成绩并统计90分以上的人数。请填空#include “stdio.h”void main(){ int n,m ; float grade,average; n=m= ;{ (“%f”,&grade);if(grade<0) break;n++;average+=grade;if(grade<90) ;m++;}if(n) printf(“%.2f\n%d\n”,average/n,m); }

有关系S(S#，SNAME，SAGE)，C(C#，CNAME)，SC(S#，C#，GRADE)。若要查找分数(grade)不及格的学生姓名(sname)，则以上正确的有？（ ） A: SELECT sname FROM s, sc WHERE grade<60 B: SELECT sname FROM s WHERE sno IN(SELECT Cno FROM sc WHERE grade<60) C: SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade<60 D: SELECT sname FROM s, sc WHERE s.sno=sc.sno OR grade<60

下面选项中，用于将表student中字段grade值更新为80的SQL语句是( ) A: ALTER TABLE student set grade=80; B: UPDATE student set grade=80 where grade=80; C: UPDATE student set grade=80 where grade<=80; D: UPDATE student set grade=80;

列出SC表中所有考试不及格的学生的学号Sno（无须重复），其SQL语句为（ ） A: SELECT DISTINCT Sno FROM SC WHERE Grade<60; B: SELECT DISTINCT Sno FROM SC WHERE Grade IS NULL; C: SELECT Sno FROM SC WHERE Grade<60; D: SELECT ALL Sno FROM SC WHERE Grade<60;

把’数据库原理‘课程分数小于60分的同学的‘数据库原理’课程分数加5分。update _______set grade=grade+5from _________________________where ________________________ A: sc ; sc join course on course.cno=sc.cno ; cname='数据库原理' and grade<60 B: course ; sc join course on course.cno=sc.cno ; cname='数据库原理' and grade<60 C: sc ; sc join course on course.cno=sc.cno ; cname='数据库原理' and grade

查询编号为'c01'的课程考试成绩在80-89之间的学生的学号,下列（）语句不能实现。 A: select sno ,grade from sc where cno='c01' and grade between 80 and 89 B: select sno ,grade from sc where cno='c01' and grade>=80 and grade<90 C: select sno ,grade from sc where cno='c01' and not (grade90) D: select sno ,grade from sc where cno='c01' and grade in (80-89)

有如下的SQL语句： Ⅰ.SELECT sname FROM s, sc WHERE grade<60 Ⅱ.SELECT sname FROM s WHERE sno IN(SELECT sno FROM sc WHERE grade<60) Ⅲ.SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade<60 若要查找分数(grade)不及格的学生姓名(sname)，则以上正确的有哪些？（ ） A: Ⅰ和Ⅱ B: Ⅰ和Ⅲ C: Ⅱ和Ⅲ D: Ⅰ、Ⅱ和Ⅲ

在学生选课数据库中，将所有选了课程‘DB’且分数在60~70分之间的学生的成绩增加百分之十，SQL语句为（ ） A: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=’DB’ AND Grade BETWEEN 60 AND 70; B: UPDATE SC SET Grade+=Grade*0.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade >= 60 AND Grade <=70; C: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade <= 60 AND Grade >=70; D: UPDATE SC SET Grade=Grade*1.1 WHERE Cno IN (Select Cno From Course WHERE Cname=’DB’) AND Grade BETWEEN 60 AND 70;

有代码为：grade = int(input())grade = grade // 10if grade == 9 and grade == 10: print('优秀')elif grade == 8: print('良')elif grade == 7: print('中')elif grade == 6: print('及格')elif grade > 0 and grade < 6: print('不及格')else: print('错误的成绩输入')请问以下说法，哪些 正确 ？ A: 如果输入90分到100分之间的分值，输出为“优秀” B: 不及格的输入条件有错误 C: 判断是否优秀的条件有错误 D: 如果输入0到10分之间的分值，输出为“不及格” E: 如果输入0，输出为“错误的成绩输入”

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)