* ZCX1.PRG
A=600
B=300
A=A+B
B=A+B
C=A+B
RETURN
*MAIN.PRG                                                                 
CLEAR
LOCAL A,B
A=80
B=60
C=A+B                                             
? A,B,C                                              
DO ZCX1                                                 
? A,B,C                                           
RETURN
执行 DO   MAIN ，写出运行结果。