Fill in the blank

The Numbers Rap
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
，
 
 
 
 
 
 
 
 
 
 
 
 
 
 
seven seven seven seven seven seven seven, seven seven seven seven seven seven seven
Hint: (numb.) seven; 7
Correct!