Answer:
num
Explanation:
In java reserved words are also known as keywords, keywords are reserve words for a language that can't be used as an identifier(name of a class, name of a variable, name of an array etc.) int, public static, are reserve words.
In given question num is not a reserved word.
Answer:
Extremal hard drive is not form of communication.
Answer:
THE OPERATING SYSTEM (OS)
Explanation: