A.SELECT 学生号 FROM 选课: MHERE 课程号=“KC1”AND 成绩>=; (SELECT 成绩 FROM 选课; WHERE 课程号=“KC1”) B.SELECT 学生号 FROM 选课; WHERE 课程号=“KC1”AND 成绩IN; (SELECT 成绩 FROM 选课; WHERE 课程号=“KC1”) C.SELECT 学生号 FROM 选课: WHERE 课程号=“KC1”AND 成绩>=ALL: (SELECT 成绩 FROM 选课; WHERE 课程号=“KC1”) D.SELECT 学生号 FROM 选课; WHERE 课程号=“KC1”AND 成绩 IN; (SELECT 成绩 FROM 选课)