A.He needs to press F7 to return to the document before he prints it. B.He has to print the document to see the page numbers. C.The printer is not working correctly. D.The numbers are on the screen but they don't print out.
【单选题】有一个学生表student,包含主键S#(学生编号)等。又有分数表SC,包含S#(学生编号)、score(分数)等。已知student表中共有50个学生,有45人参加了考试(分数存在SC表中),其中10人不及格。执行以下SQL语句:select * from student where exists (select S# from SC where score<60 ),可返回_________条...
【单选题】有一个学生表student,包含主键S#(学生编号)等。又有分数表SC,包含S#(学生编号)、score(分数)等。已知student表中共有50个学生,有45人参加了考试(分数存在SC表中),其中10人不及格。执行以下SQL语句:select * from student where exists (select S# from SC where score<60 ), 可返回_________...