第24题: [单项选择]下列哪一条指令是合法的( )。 A. OUT DX,AL B. MOV DS,1000H C. XCHG [DI],[SI] D. MUL BL,2 参考答案:A 答案解析:[分析] 把AX或AL中的内容传送到一个输出端口。端口地址可以用直接寻址(OUT AL n),也可用DX间接寻址(OUT AL,DX)。8位地址直接寻址,可寻址256个端口:DX间接寻址,可寻址64K
第32题: [单项选择]{{I}}Questions 22~25 are based on the following monologue.{{/I}}What is the substance in cigarettes that causes cancer A. Cigarette ashes. B. Nicotine. C. Tar. D. Not mentioned here. 参考答案:C