🗂 Data Declaration Declare variables: s1 db 1 - s1 is 1 byte, with value 1. s2 db ? - s2 is 1 byte, uninitialized. s3 db 10 dup(?) - Array of 10 elements, uninitialized. s4 db 'a' - Character type. s5 db 'thao xinh gai$' - String type, ends with $.