问题 填空题


下面程序是动态显示程序,请分析程序完成说明。
MOV DPTR,#4400H
MOV A,#03H
MOVX @DPTR,A
SETB RS0 ;使用第1组工作寄存器
MOV R2,#08H
MOV R0,#30H
CLR A
L1: MOV @R0,A
INC R0
INC A
DJNZ R2,L1
DISP: MOV R0,#30H ;显示缓冲区首址送R0
MOV R1,#00H
MOV R2,#08H ;R2中的08H表示①
MOV R3,#7FH ;选中最右端LED
DISP1: MOV A,@R0 ;第2次执行时A=②
MOV DPTR,#TAB ;指向字形表首址
MOVC A,@A+DPTR ;第2次执行时A=③
MOV DPTR,#4402H ;4402H表示④
MOVX @DPTR,A ;该条指令的作用是⑤
MOV A,R3 ;第2次执行时A=⑥
MOV DPTR,#4401H ;指向位选口
MOVX @DPTR,A ;位码送PA口
DJNZ R1,$ ;
DJNZ R1,$ ;该指令的作用是⑦
RR A ;位选字移位
MOV R3,A ;移位后的位选字送R3
INC R0 ;在本程序中,R0最大取值为⑧
MOV A,@R0 ;缓冲区数据送A
DJNZ R2,DISP1 ;未扫描完,继续循环
SJMP DISP
TAB: DB 3FH,06H,5BH,4FH,66H;共阴极LED字形表
DB 6DH,7DH,07H,7FH,6FH
答:①______;②______;③______;④______;
⑤______;⑥______;⑦______;⑧______。

答案

参考答案:④PB口地址

阅读理解

In England, afternoon tea, taken between four and five, is the most informal(非正式的) meal of the day. If you are a friend of the family, you may drop in for tea without an invitation(邀请) or telling that you are coming. Very often it is not served at a table. The members of the family and visitors take tea in the sitting room. Each person has a cup and saucer(托盘),a spoon and a small plate for bread-and-butter and cake. By the way, do not help yourself to cake first; bread-and-butter first, then cake if there is any. Another piece of advice: Do not put more than one piece of bread or cake on your plate at the same time.

6.Afternoon tea is usually taken with __________.

A. in the morning                  B. between four and five   

C. in the early afternoon              D. in the evening

7.If you want to have afternoon tea in a friend’s home, ___________.

A. it is necessary for you to send a message

B. you should wait for his invitation

C. it is impolite for you to go there without taking anything with you

D. it is not necessary for you to call him or send a message.

8.In the passage, “drop in” means “_________”。

A. pay an informal visit       B. fall down   

C. drink at a friend’s home       D. break

9.It’s impolite for you to _________.

A. help yourself to cake first      

B. share a cup with your friend

C. put more than one piece of bread or cake on your plate once

D. all of the above

10.Which of the following is not true?

A. Afternoon tea is often taken in the sitting room.

B. The members of the family often share a cup and saucer, a spoon, etc.

C. Afternoon tea is usually taken between lunch and supper.

D. Help yourself to bread-and-butter before cake if there is any.

多项选择题