以下MySQL语句中,已知关系模式stu_course(Sno,Cno,Term,Grade),查询grade在70到79之间,并显示 sno和grade的记录,正确的是( )。 A. SELECT sno,grade FROM stu_course WHERE grade>=70 AND grade<=79; B. SELECT sno,grade FROM stu_course WHERE grade BETWEEN 70 TO 79; C. SELECT sno,grade FROM stu_course WHERE grade>=70 OR grade<=79; D. SELECT sno,grade FROM stu_course WHERE grade BETWEEN 70 AND 79;