已知下列程序段: DATA SEGMENT X1 DB 12H,34H,0,56H X2 DW 78H,90H,0AB46H,1234H ADR1 DW X1 ADR2 DW X2 BUF DB 5 DUP(0) DATA ENDS CSEG SEGMENI ASSUME CS:CSEG,DS:DATA mov ax,data mov ds,ax XOR CX,CX MOV CL,3 ADD ADR1.CX SUB ADR2,CX MOV BX,ADR1 MOV DI,BX MOV SI,ADR2 MOV AL,X1「BX」 MOV BUF「DI],AL MOV AX,X2[BX][SI] MOV WORD PIR BUF,AX CSEG ENDS 上述程序运行结束后,BUF中各字节单元内容是什么?