20以内三连减口算练习题(21).docx

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1、20-1- 16=13-5-1=17-8-2=16-2- 10=16-8-8=10-9-1=11-7-2 =17-3- 14=18-2-9=16-11-2=20-3- 12=12-7-5 =20-13-5 =17-2-15 =18-7-7=20-8 - 12 =20-7-6=18-8-9=14-5-3 =17 - 15 - 1二10-6-2 =15-4-7=17 - 11 - 3 二10-2-1=19 - 2 - 11= 20-8-11=18 - 10 - 8=16-4-2=20-8 - 10=17 - 10 - 2=13-3-1 =17-2-1=17-3-9=12-3-1=20-4-2 =1

2、7 - 12 - 1=9-3-1=15-1-6=20-5-3二13-1-4=13-2-1=6-1-3=12-3-4=19-7-1 =11-3-5=13-4-8=11-6-1=16 - 5 - 11=17-8-6=14-1-9=20 - 17 - 2=8-5-3=13-4-1=13-2-3 =17-7-9=13-3-8=17-7-6=10-7-2 =14-4-7=19-8-7=14-1- 10=10-5-3 =17 - 13 - 1=16-4-11 =15-4-5 =19-5-13 =20-6-3=15-7-4=13-4-3 =18-1-8=19-1- 16=15-2-3二4-2-2=5-2-2

3、二9-3-2二16-5-6二18-8-3 二19-2-2二20-3 -15 =12-3-9二20-2 -10=14-2-5 =8-5-1=17-1-15 =16-2-4=19 - 11 - 5=18-11-2=14-3-3 =15-6-3 =14-6-1=14-8-3二5-1-3=20-1- 12 =13-6-5 =16 - 1 - 13 =19-5-3 =20 - 16 - 2=19-4-5 =10-3-3 =19-2- 13 =16-2-12 =20-1-5 =20-4-16=18-6-7=14-3-1=9-6-3=8-4-3二19-8-9=15 - 5 - 10=15-2-6=10-3-

4、2 =8-6-1=7-1-1=16-10-1 =20-3- 14=16-3-6=19-1- 10=14-8-4=10-5-2=6-2-4=17 - 10 - 3二12-4-7=9-5-4=19-5-2=19 - 1 - 13 =20 - 15 - 5=16 - 15 - 1=13-6-7=17-6-7=17-1-8=14-6-8=17-2- 12 =14-1-1=5-1-2=18-6- 10=15-13-2=14-4- 10=20-2-8=20-2-9=16 - 3 -13=14-2-8=16-8-4=14-4-9=18-5-9=16-3-8=15-5-9=20-7-7=18-3-5=20 -

5、15 - 2=17-8-9=13-2-9=12-5-1=17-5-9=11-2-1=12-4-5 =14-3-6=12 - 11 - 1二12-6-4=18 - 10 - 2 =20-1-13 =16-4-5 =19-3-5=17-5-12 =20-2-4=16-1-11 =13-1-6=16-2-5 =20 - 19 - 1二20-11-5=13-7-2=19-9-5 =5-4-1=17-7-7=19-6-6=18 - 12 - 4=14-4-2 =11-2-5 =12-4-8=20-1- 18=20 -18 - 2=15-3-11=7-1-6-4-2-1=20 - 3 - 10= 13-1

6、-5 =17-5-4=13-5-8=20-13-2=16-3- 10=19-4-11=16-3-3 =13-2- 10=15-1-5=17-3-1=13-7-4=19 - 13 - 4=9-7-2=16-3-11 =19-8-5 =15-8-6=7-2-3=19-9- 10=12-4-6=19-8-4=20-6-13 =20-9-9=4-1-3=13-8-2 =5-1-1=13-5-4=14-1-7=14-2-6=13-4-9=16-2-3 =18-9-7=17-10-1 =19-9-8=18-2- 10=19-3- 16=6-1-4=20-6-4=20-1- 17=20 -12 - 5=13

7、-1-1=17 - 12 - 5 =17-2-2 =19-1-9=19-4-1=5-1-4=20-17-3 =8-5-2=6-4-1=15-6-8=19-3-9=11-1-3 =19-6-9=10-4-6=18-3-8=11-8-3 =13-11-1 =12-3-2 =18 -16 - 2=17 - 3 - 10=19-3-3 =12-2-4=19-7-8=17 - 12 - 2 =17-6-5 =17-3-3 =20-8-5=19-5- 12 =16-11-4=19-11-3 =19-2-1=14-9-1=13-8-1=14-5-9=8-2-1=17-1-6=11-2-9=18-15-2 =

8、9-2-7=10-1-2 =19-4-4=11-4-2 =14-3-2 =16-2-11 =19-3-1 =14-1-8=18 - 10 - 5= 19-5-7= 19-2-6=17-3-13 =14-7-3 =18-6-4=10-4-3 =16-5-1 =20 -12 - 4=8-4-2=20 - 14 - 6= 15-9-4=19 - 12 - 4=16-9-2 =13-1-2 =16-8-1 =17-6-11=10-4-2 =16 - 10 - 6=17-4-9=14-6-3 =3-1-2=17 - 12 - 3二19 - 10 - 5=13-2-5 =17-15-2 =14-9-3 =

9、11-1-6=19 - 14 - 4=15-4-11=10-4-1=9-4-4=18-7-9=18-9-5 =10-1-8=20-1-7=18-7-4=15-6-4=16 -13 - 2=18-5-6=19-8-8=20-3- 16=18-3-14=6-2-2=17-8-5 =19-1-8=19 - 16 - 2=15 - 11 - 3二20-8-4=15-11-1 =16-1- 14=20-9-5 =15-7-6=19-4-15 =19-6 - 10=20 - 12 - 1=14-7-2 =19-6 - 12 =20-2-5 =12-10-2=20-9-1=14-5-7=8-2-3=18-2

10、- 16=17-9-8=20-16-3 =20-7-11 =17-16-1 =19 - 3 - 14=17 - 11 - 6二19-1-5 =18 - 5 - 12 =18-7-3 =17-8-4=7-2-4=12-8-2 =15 - 12 - 1=18-1-7=15-10-3 =12 - 1 - 11=18-9-9=12-1-7=16-6-6=15-8-5 =16-9-3 =15-9-2 =11-5-3 =14 - 11 - 1=18-6-3 =20-4-13 =15-1-2 =18-2- 12=6-2-3=20 - 14 - 1 二 10-2-4=14 - 12 - 1二16-6-5 =1

11、2-1-9=15-7-3 =20-6-8=17-4-10=3-2-1二16-7-5 =19-6-13 =14-3-5=17-4-8=19 - 13 - 1=20-11-2=19-4-7=20-6-9=18-5-7=17-4-11 =19-4-12=12-5-4=18-9-3 =20 -11 - 6=19-14-1 =8-1-2=9-2-1二20 - 12 - 6=19-2-3 =17-2-6=18-2-4=10-3-5 =14-7-4=17-1- 12 =20-3-4=16-1-4=10-2-2 =20-6-5 =18-5-4=13-9-4=18 - 3 - 13=20-3-6=11-4-5

12、=14-6-5 =13 - 1 - 12 =3-1-1=20-4- 10=16 - 13 - 3 =18-1-4=19 -13 - 2=8-2-2=16-2-2 =16-3-5=16-6-3 =14-2-3 =14-2-7=13-10-3 =14-11-3 =17-9-1 =12-2- 10=20-4-9=15-5-3 =12-3-6=10-1-1=17-1-3 =19-5-1=20-4-6二7-4-3=11-3-4=12-1-6=18-9-8=19-3-8=16-1-8=11-2-4=18-6-8=12-6-5 =7-2-5=20 - 12 - 7=17-11-2 =14 - 13 - 1二

13、20-8-1 =11-2-8=9-1-7=18-2-2 =17-2-11 =5-3-2-18-4-7-15 - 1 - 13 =17 - 13 - 3二19-1-1=19-8-11=19-5-6=19-9-9=11-3-8=19-16-1 =18-7-6=14-6-4=18-3-7=20 - 5 - 13=15-2-12 =12-5-7=18-1-6=11-10-1=20-2-3 =9-4-1=17-6-4=14-2-9=18-2-1 =20 - 14 - 4=6-1-2=19 - 11 - 1=13-3-9=19-7-11=19-4-3 =11-4-3 =17 - 10 - 4=18 - 1

14、0 - 4=19-15-2=15-3-4=12-5-6=9-3-4=12-5-3 =19 - 10 - 8=12-1-2 =13-6-2=16-1-15=14-5-1 =13-4-4=16-1-9=12-1-5 =16-3-4=17-1- 14=14-3-8=16-2- 14=17-4-13 =15-10-4=19-7-9=15-6-6=17-2-9=8-3-5=20-8-2 =18-6-11=20-4- 14=19-9-1=14-2- 11=16-1-2 =20-5-2 =20 -11-4=13-1-9=19-14-3 =20-6-1=12-7-4=19-3-13 =20-7-2=16-7-

15、2二15-1-3 =18 - 11 - 3 二19-2- 14=20-1-15 =20-2- 16=11-7-4=16-1-6=18-5-8=16-2-6=18-3-3 =19-9-4=14-2-1=13-5-7=16-8-2 =20-4-12=10-8-2 =10-1-5 =18-11-1=15-7-1=9-6-1=12-5-5 =17-6-2 =12-9-3 =18-3-4=5-2-3=14-5-8=9-6-2=18-1-9=14-2-2 =14-7-6=9-2-3=19 - 17 - 1=13-3-2 = 20-5-4= 15-7-2二18 - 3 - 11 = 18-8-5=16-1-

16、 10=19 - 10 - 2= 20-9-3 =17-3-2 = 14-6-7= 20-2-1=15-2-9=16-5-5=19 - 3 - 11=20 - 5 - 10= 20-7 - 10=19-3-15 = 20-11-9=19 -10 - 9=2-1-1=17-5-2 =12-1-1=9-8-1=10-3-7=20-4-7=18-4-13 =17-5-3 =18-3-2 =14-8-6=12-2-9=17-9-7=20-8-9二19-6-2 =11-1-8=20-6-11=19-7-3 =17 - 13 - 4=16-7-6=16-6-4=10-8-1=18-4-12=19-8-6=

17、16-9-5二15-1-7=20-5- 12 =6-3-3=13-1-3 =19-2-15 =17-9-2 =20-9-6=13-7-3 =15-9-6=18-1-12 =19-8-1=12-6-6=11-7-3 =17-2-7=13-3-6=13-1-7=20-7-9=14-4-6=20-2- 18=10-4-4=19-6-7=20-3-1=15-7-8=19 - 10 - 6 二16-6-7=16-7-8=20 - 10 - 2=17-8-1=14-2- 10=20-9-11 =13-4-2=11-3-1=19 - 12 - 7=12-9-2=10-2-6=19 - 11 - 7=15-9

18、-1=17 -7 - 10=14-10-2 =13-2-6=16-1-1 =20-5-9=18-5-1=9-2-2=20-7-4=8-1-7=19 - 1 - 14=20-5-1 =15-1-9=15 - 10 - 5=18-1- 14=12-5-2 =9-3-6=15-11-4=11-4-7=14-10-3 =14-1-5 =11-5-5 =17-14-2 =19 - 12 - 1 =18-6-5=20-5-7=20-8-3 =10-2-3 =19 - 10 - 1 =18-1-15 =13-8-5 =11-3-6=18 - 17 - 1=20 - 12 - 3 =10-3-6=11-4-6

19、=15 - 12 - 3二16-9-6=18-5-5 =17-5-5 =17-9-5 =19-1-3 =6-3-2=19-1-11=13-3-3 =18 - 12 - 3 =12-4-1=16-8-7=16-7-7=20-15-1=16 - 14 - 1=19-3-7=19-10-3 =13-11-2 =10-1-7=16-5- 10=18-7-8=16-3-7=20-1-9=19-11-2 =15-9-3 =13-5-3 =20 -13 - 3=18-8-10=19-9-2=17-9-3 =17-7-1=18-5-2 =19-1-4=10-3-4=16-6 - 10=18-6-6=19-3-

20、4=18-14-2=12-1-4=15-3-6=20 -13 - 4=6-4-2=13 - 10 - 1=20 - 10 - 9=20-5-5 =18-12-2 =16-11-5 =14-1-4=17-6-9=13-4-7=19-5-9=11-1-5 =18-15-3 =20-7-8=16-6-2 =20 - 14 - 5=16 - 12 - 3二9-1-4=12-3-3 =18-7-1=14-11-2 =20 - 10 - 5=18-2-11=12-6-1=19-4-6=12-1-8=18-7-5=15-6-1=16-3-9=11-9-2=17-1-5 =18-4-1=17-5-8=13-7

21、-6=16-7-3 =14-7-1=20-2-13 =19 - 14 - 2=19-7-4=18-10-3 =18-4- 14=17-8-3 =15-1-1=15-6-2 =19-5- 10=8-7-1=20-7-13 =18-4-10=8-2-6=18-14-1 =17-2- 10=14-6-2=20 - 16 - 4=16-4-1 =10-1-3 =20-9- 10=19 - 12 - 3二20-3-8=19 - 17 - 2 =8-4-4=18 - 11 - 6=20-4-15 =18-4-9=20-1-4=16-4-4=16-5-2 =9-5-1=7-6-1=10-7-1=18-9-4

22、=20-3-9=19-7-2 =10-2-7=16 -12-4=15 - 13 - 1=16-6-8=15-12-2=15-2-2 =15-1-8=16-3-1=20-2-7=20-2-2=10-6-4=19 -13 - 6=15-3-3 =17-5-6=18 - 1 - 11 =18 -11 - 7=20-4-4=11-6-3 =15-4-8=8-3-4=10-7-3 =20-7-3二16-7-9=18-6-2 =15-8-2二15-1-4=19-7-5 =17 - 12 - 4=18-1-13 =19-5-5=17-9-4=14-5-2=9-1-3=16 - 14 - 2= 16-1-12

23、 =13 - 1 - 11 =19-8-2 =20-7-12 =20-6-2 =18-8-7=18-2-7=7-1-4=12-7-3 =15-3-2 =9-2-6=20-7-5二20-6 - 14=15-4-10=7-2-2=19-1-2 =18 - 15 - 1=20-9-8=18-11-4=18-2-5=16-7-1=13-8-4=18-1-2=18-7-2 =10-6-1=14-3-7=13-5-2=16-2-9=18-8-4=18 - 13 - 3 =19-3-10=19-7-6=15-6-5=9-1-8=16 -11 -1=18 - 12 - 6=11-1-7=13-5-5=20-1

24、-6=12-7-2 =17-4-4=20-3-3 =8-4-1=20 - 10 - 10=18-2-15=13-9-1=14-2-4=9-3-1=15-1-6=20-5-3 =13-1-4=13-2-1=6-1-3=12-3-4=19-7-1=11-3-5=13-4-8=7-1-5=15-4-3 =9-4-3=12-4-3 =18-7- 10=17-4-3 =20-1- 16=13-5-1=17-8-2 =16-2- 10=16-8-8=10-9-1=11-7-2 =17 - 3 - 14=18-2-9=16-11-2=20-3 - 12 =12-7-5 =13 - 12 - 1=19 - 1

25、0 - 7=18-4-8=14-8-1二14-3-4=14-5-3 =17 - 15 - 1=10-6-2 =15-4-7=17-11-3 =10-2-1=19-2-11 =20-8-11 =18 - 10 - 8=16-4-2 =20-8- 10=17-10-2 =16-5-11=17-8-6=14-1-9=20 - 17 - 2 =8-5-3=13-4-1=7-5-2=17-2-3 =14-2- 10=20-9-11 =13-4-2 =11-3-1=19 - 12 - 7=12-9-2 =10-2-6=19-11-7=15-9-1=17-7- 10=17-2-15 =18-7-7=20-8

26、- 12=20-7-6=18-8-9=15-5-8=19-7-3 =17 - 13 - 4=16-7-6=16-6-4=10-8-1=18-4-12=19-8-6=16-9-5=15-1-7=20-5- 12 =6-3-3=13-1-3 =17-3-9=12-3-1=20-4-2 =17 - 12 - 1=15-2-11 =19-8-1=12-6-6=11-7-3 =17-2-7=13-3-6=13-1-7=20-7-9=14-4-6=20-2- 18=10-4-4=19-6-7=20-3-1 =13-2-6=16-1-1=20-5-9=18-5-1=9-2-2=20-7-4=17-2-13

27、=14-9-4=19 - 13 - 3=16-10-3 =17-8-7=20-2- 14=18-3-12 =17-4-7=13-3-4=4-3-1=16-12-1 =11-5-2=17-9-2 =20-9-6=13-7-3 =15-9-6=18 - 1 - 12 = 19-4-13 =16-4-12=20-8-6=14-1-3 =20 - 12 - 8=15-2-8=11-2-3 =13-6-4=18-4-11=18-8-8=19-2- 12 =20-3-5 =14-8-5 =16-6-7=16-7-8=20 - 10 - 2=17-8-1=15-7-5二16-4-7=8-3-3=15-4-2

28、 =9-3-3二16-2-1=12-3-7=17 - 5 - 11=20-11-3 =18-9-2 =16-1-7=14-5-6=20-5-11 =16-8-3 =15-4-4=17-7-5=19-4-9=8-6-2=16-4-9=19-9-7=15 - 10 - 2=18 - 10 - 6=20-2- 17=20-6-6=12-2-2 =19 - 15 - 1=17 - 14 - 1=12-2-3 =6-5-1=14-1-13 =20-8-7=20-1-3 =17-5-7=18-2-3 =20 - 11 - 7=19-7- 10=12 - 10 - 1=16-4-3 =20-4-3 =17-

29、7-4=14-5-4=13-3- 10=12-6-3 =14-3- 10=16-3-2=17-4-1=14-7-5 =11-1-4=18 - 12 - 5=18-3-1 =16-11-3 = 17-5-1=18-14-3 =14 - 10 - 4= 17-1- 10=20 - 3 - 11= 16-4-10=18-9-1=20-1- 19= 13-6-6=15-5-6=20 -13 - 7=17 - 1 - 13 =7-4-1=6-1-5=16-4-8=18-13-4=20-11-1=16 -12 - 2=12-2-6=15-2-5 =10-1-4=13 - 10 - 2=20-5-6=13-

30、5-6=17-3-6=19 - 18 -1=13-9-2 =19-6-1 =19-2-9=20-5-15 =12-6-2 =19-2- 17=18-7-11 =17-3-4=20-6-12 =17-1-4=15-6-7=8-1-3=15-11-2=20-1- 10=19 - 5 - 14=10-3-1=14 - 12 - 2 =16-8-6=10-2-8=18-13-2 =9-1-1=17-3-5=18-1- 17=12-1- 10=14-8-2 =错误率,PH14-3-9=11-3-3 =20-6 -10=18-1-1=8-3-2=10-5-1=19-2-4=15-8-4=11-1-9=15

31、-5-4=20-2-6=18-8-2 =17-14-3 =20 - 13 - 1=13-9-3 =14-4-4=19-8-3 =17 - 10 - 7=19-1-15 =20-10-1 =17-7-8=20 - 13 - 6=12-2-1 =14-1-6=19 - 12 - 5二12-2-7=16 - 10 - 2=15-1- 14=19-1- 12 =18-1- 16=18-11-5=20-2-15 =19-6-8=14-4-3 =18-1-3 =18-9-6=9-1-5=20 - 10 - 7=12-9-1=15-8-1 =19-6-3 =19 - 5 - 11=9-4-2=7-5-1=1

32、8-3-6=13-2-4=15-3-5 =18-5-3 =18 - 12 - 1 =13-2-7=20-4-11 =11-6-4=18-3-15 =14 - 10 - 1 二17-4-5二16-7-4=7-3-1二7-1-2=16-5-7=18-2- 14=17 - 1 - 11 =19 - 12 - 2=11-4-1 =18 - 13 - 1=17-4-2 =17-2- 14=16-5-8=20-3- 17=15-2-7=14-4-5 =20-3-13 =16-4-12=20-8-6=14-1-3 =20 - 12 - 8=15-2-8=11-2-3 =13-6-4=18-4-11=18-8

33、-8=19-2- 12 =20-3-5 =14-8-5二20-7-1=20-1-3 =17-5-7=18-2-3 =20 - 11 - 7=19-7- 10=16-4-7=8-3-3=15-4-2 =9-3-3=16-2-1=12-3-7=17 - 5 - 11=20-11-3 =18-9-2 =16-1-7=14-5-6=20-5-11=19-4- 10=10-4-5 =18-3-1=16 - 11 - 3二17-5-1=18-14-3 =19 - 13 - 3二16-10-3 =17-8-7=20-2- 14=18 - 3 - 12 =17-4-7=13-3-4=4-3-1=16 - 12

34、 - 1=11-5-2=18-2-6=16-8-3 =15-4-4=17-7-5 =19-4-9=8-6-2=16-4-9=14-5-5 =20-2-12 =17-4-6=11-4-4=16-1-3 =19 - 13 - 5=16-1-5 =4-1-2=20 - 14 - 3=19-6-11 =20-16-1 =19-4- 14=15-2-1=9-5-3=15-1- 10=12-4-2 =15 - 3 - 12 =16-10-4=20-4-8=20-2-11 =9-5-2=16-9-4=16-9-7=17-3-7=11-3-7=6-2-1=17-2-8=17-6-1 =19 - 1 - 18=

35、15-8-3 =20 - 18 - 1=18 - 3 -10=17 - 11 - 1=11-1-2 =16-6-1=7-2-1=19-3-2 =12-8-1=11-1-1=19-4-8=18-2-8=13 - 1 - 10=20-4-1 =13-7-5 =17-6 - 10=5-3-1=18-2-13 =11-8-1=18-6-1=17-6-8=15-3-1=20-1-8=15-5-1=18-4-2 =19 - 10 - 4=15 - 3 - 10=17-8-8=7-1-3=19-5-8=11-5-4=12-4-4=20-10-3 =20-9-2二13-3-5=15 - 1 - 11 =13-

36、6-3 =20-15-3 =18 -13 - 5=11-2-6=19-15-3 =14-1-11 =16-2-8=17-1-7=20-9-7=17-7-3 =14-9-5=7-3-2=19-1-6=16 - 13 - 1=7-4-2=16-2-7=18-8-6=19-16-3 =20-1-2 =13-7-1=18-5-13 =20-4-5 =17-13-2 =11-5-6=18 - 14 - 4=18-4-3 =16-10-5 =11-3-2 =15-5-7=20 - 1 - 11=18-4-4=19-9-3 =15-9-5 =19-11-8=17-4-12 =11-8-2 =16-4-6=1

37、7-1-9=5-2-1=20-1- 14=20-1-1=20-15-4=17-3-8=20-8-8=20-5-8=20 - 10 - 4=17 - 10 - 6=15-14-1 =8-3-1=14-9-2=14-4-8=15-2-4=11-2-2 =8-1-6=16-5-4=12-2-5 =20-9-4=9-3-5=19-3- 12 =19-4-2 =18-1- 10= 15-4-1 =18-6-9=16-9-1 =11-5-1=19-5-4=11-9-1=9-1-2=11-7-1=17-2-5 = 11-6-5 =18-4-5=20 - 17 - 1 = 15-8-7= 17-1-2 =9-

38、1-6=15-5-2 =错误率：18-6-12= 17-2-4= 11-6-2 =18 -16 - 1=20 - 5 - 14= 19-2- 16=15-3-9=17 - 11 - 5 二 8-1-5=19-6-4=17 - 10 - 5二19 -11-4= 15-4-6=19-7-12 =18 - 5 - 11= 14-2-12 =16-5-9=19 -15-4=13-8-3 =9-7-1二16-6-9=6-1-1=19-7-7二9-2-4=19-9-6=11-1- 10=14-6-1=14-8-3 =5-1-3=20-1- 12=13-6-5=16-1-13 =19-5-3 =20 -16

39、 - 2=19-4-5=10-3-3 =16-5-3 =7-3-4=8-1-1=15-5-5=14-1-2 =17-6-3 =13-2-3 =17-7-9=13-3-8=17-7-6=10-7-2=14-4-7=19-8-7=14-1- 10=10-5-3 =17 - 13 - 1 二 16-4-11=15-4-5 =19-2-7=18-8-1=10-1-6=18-10-1 =18-4-6=15-2-3 =4-2-2=5-2-2=9-3-2=16-5-6=18-8-3 =19-2-2 =20-3-15 =12-3-9=20-2- 10=14-2-5 =8-5-1=16-2-12 =20-1-5

40、 =20-4-16=18-6-7=14-3-1 =9-6-3=20-11-8=10-6-3 =14-4-9=18-5-9=16-3-8=15-5-9=20-7-7=18-3-5=20 -15 - 2=17-8-9=13-2-9=12-5-1 =20-6-3 =15-7-4=13-4-3 =18-1-8=19-1- 16=13-6-1=8-4-3=19-8-9=15-5- 10=15-2-6=10-3-2 =8-6-1=7-1-1=16 - 10 - 1=20-3- 14=16-3-6=19-1- 10=14-8-4=错误率,PH16-2-4=19 - 11 - 5 =18 - 11 - 2=14-3-3 =15-6-3 =17-9-6=19 - 1 - 13 =20-