A.INC [BX]
B.CMP [BX]，20
C.JMP FAR OPR
D.MOV WORD PTR[BX]，20

A.20H
B.21H
C.22H
D.23H

A.DI=0104H，CX=0000H
B.DI=0103H，CX=0001H
C.DI=0102H，CX=0002H
D.DI=0101H，CX=0003H

A.AX=0032H
B.AX=00E0H
C.AX=03E0H
D.AX=0FFE0H

A.把地址2000H送SI
B.把地址2000H字单元的内容送SI
C.把地址2000H字单元内容送SI，把2002H字单元内容送ES
D.把地址2000H字单元内容送ES，把2002H字单元内容送SI

A.2000H
B.2002H
C.1FFCH
D.1FFEH

A.XCHG AL，DS
B.XCHG BH，[BX]
C.XCHG AL，OFH
D.XCHG BUF1，BUF2

A.JNS
B.JZ
C.JS
D.JC

A.NEG AL
B.NOT AL
C.INC AL
D.DEC AL

A.CLC
B.CMC
C.STC
D.NOP

A.IDIV 2
B.SAR DX，1
C.DIV 2
D.RCR DX，1