单项选择题
A.XCHG AX,DI B.XCHG BX,[SI+3] C.XCHG AL,20H D.XCHG NUM,DX
A.MOV AX,1234H B.MOV BX,[1234H] C.MOV DS,AX D.MOV 2000H,AX
A.直接寻址 B.立即寻址 C.寄存器寻址 D.寄存器间接寻址