Echo Array cell value not fully solution

Echo Array cell value is not complete
Array for the

Array
(
[title] = The top of the book Math test
[id] = 6
[Subject] = 14
[Parts] = [["Radio", "100", 1]]
[Topic] = [["1", "100"]
[JSON] = [["6", "
Little Red does a math problem "
  
   '; Color:rgb (0,0,0); font-weight:bold;font-size:14px;font-family:
   
[#39; ' > Two polynomial
   
    ' Font-family:times New Roman ' >a
    ,
    B
    ,
    B
    to be
    , try 
      
       ' font-family:times New Roman ' >a B
       
    the value
    ". Little Red mistakenly will 
      
       ' font-family:times New Roman ' >a B
       
    considered
    A
    -
    
     
      '; Color:rgb (0,0,0); font-size:14px;font-family:
      
[#39; ' >b 
      
       ' font-family: Song body, the result answer (calculated correctly) is 
       .  
      

     
    
   
  
 
  
   ' text-indent:21px;line-height:200% ' > 
   ( 
    
     ' font-family:times New Roman ' >2 
      
   ) Find out when 
    x 
   
     '; Color:rgb (0,0,0); font-size:14px;font-family:
    
[#39; ' ] = 3 
    at 
    the value of 
    a B 
    .
  
  
  
  
    

  
    

", 1," 100 "]]
    
[Total] = 100
    
)
    

 
   
 
 
 

  
 

I'm printing the JSON keys, but I'm not printing them all, showing

 
 [["6", "
 share to:  , the math test???? [Id]?=>?6???? [Subject]?=>?14???? [parts]?=>?              [["Radio ", ...." Data-pics= "" >  
 
 
 
------Solution--------------------
 Please output the Var_export ($ARR) structure; 
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