从键盘输入3个学生的成绩,如果低于60分,则F (Fail),如 果高于或等于90 分则显示 G (good),否则显示 P (Pass)。编写8086汇编语言实现分别显示成绩等级

好的，我理解了你的问题。下面是汇编代码实现：

DATA SEGMENT
    GRADE1 DB ?
    GRADE2 DB ?
    GRADE3 DB ?
    MSG1 DB 'GRADE 1: $'
    MSG2 DB 'GRADE 2: $'
    MSG3 DB 'GRADE 3: $'
    MSG4 DB 'GRADE 1: ', 2 DUP (' '), '$'
    MSG5 DB 'GRADE 2: ', 2 DUP (' '), '$'
    MSG6 DB 'GRADE 3: ', 2 DUP (' '), '$'
    MSG7 DB 'FINAL GRADE: $'
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE, DS:DATA
START:
    MOV AX, DATA
    MOV DS, AX

    ; input first grade
    LEA DX, MSG1
    MOV AH, 09H
    INT 21H
    MOV AH, 01H
    INT 21H
    SUB AL, 30H
    MOV GRADE1, AL

    ; input second grade
    LEA DX, MSG2
    MOV AH, 09H
    INT 21H
    MOV AH, 01H
    INT 21H
    SUB AL, 30H
    MOV GRADE2, AL

    ; input third grade
    LEA DX, MSG3
    MOV AH, 09H
    INT 21H
    MOV AH, 01H
    INT 21H
    SUB AL, 30H
    MOV GRADE3, AL

    ; display grades
    MOV AH, 09H
    LEA DX, MSG4
    MOV DL, GRADE1
    ADD DL, 30H
    MOV MSG4+7, DL
    INT 21H

    MOV AH, 09H
    LEA DX, MSG5
    MOV DL, GRADE2
    ADD DL, 30H
    MOV MSG5+7, DL
    INT 21H

    MOV AH, 09H
    LEA DX, MSG6
    MOV DL, GRADE3
    ADD DL, 30H
    MOV MSG6+7, DL
    INT 21H

    ; calculate final grade
    MOV AL, GRADE1
    ADD AL, GRADE2
    ADD AL, GRADE3
    MOV BL, 3
    DIV BL

    ; display final grade
    MOV AH, 09H
    LEA DX, MSG7
    CMP AL, 90
    JGE GOOD
    CMP AL, 60
    JL FAIL
    MOV DL, 'P'
    JMP DISPLAY

GOOD:
    MOV DL, 'G'
    JMP DISPLAY

FAIL:
    MOV DL, 'F'

DISPLAY:
    MOV MSG7+12, DL
    INT 21H

    MOV AH, 4CH
    INT 21H
CODE ENDS

END START

这段代码会要求用户输入三个学生成绩，并将它们存储在内存中。接着，它会计算这三个成绩的平均值，并根据平均值的大小来显示最终成绩等级（G、P或F）。