46．若有定义和语句：
        int x ；float  y ；char  z[10] ，c ；
        scanf (”%3d%f%3s%c” ，&x，&y，z，&c)；
    执行时输入12345└┘└┘└┘book└┘$↙
    则x的值是[51],y的值是[52],z的值是[53],c的值是[54]         
  
  [51]A.12345       B. 45       C. 123           D. 无答案
  [52]A.123.0        B. 45       C．  45.0       D．无答案
  [53]A.└┘└┘└┘   B. book      C.  boo        D.无答案
  [54]A．$           B．└┘        C．  k          D．无答案

47.若执行下面程序时输入pen↙
                       book↙   
   #include<stdio.h>
   #include<string.h>
   main()
   {char a1[5],a2[5]；scanf(”%s”,a1)；gets(a2)；
    puts(a1)；puts(a2)；printf(”%d\n”,strlen(a2))；}
  则结果是

[55]    A. pen       B. pen  book      C. pen    D.无答案
           book                                                
           4            0                 0


50．若执行下面程序时输入pen↙
                        book↙            
     #include<stdio.h>
     #include<string.h>            main()
    { char a1[5],a2[5]；gets(a1)；gets(a2)；
      puts(a1)；puts(a2)；printf(”%d\n”,strlen(a2))；}
   则结果是
[58]A. pen       B. pen  book       C. pen      D. 无答案
                                       book        
        0           0                  4

51．若执行下面程序时输入aa└┘bb↙   
                        cc└┘dd↙  
 #include<stdio.h>
 main()
 { char a1[5],a2[5],a3[5],a4[5]；scanf(”%s%s”,a1,a2)；gets(a3)；gets(a4)；
   puts(a1)；puts(a2)；puts(a3)；puts(a4)；}

则结果是

   [59]A． aa        B． aa     C． aa         D． aa└┘bb
           bb            bb         bb             cc
           cc└┘dd      cc                        dd
                         dd        cc└┘dd