Classify each of the following items into at least three categor

Classify each of the following items into at least three categories and state your principle of classification.
a. My friends
b. Fruit juice
c. Books in our library
【正确答案】：a. My friends can be classified according to political beliefs, taste in clothes, study habits, hobbies, temperament, the role they play in my life, etc.
b. Fruit juice can be classified according to its form (liquid or powdered), price, flavor (orange, apple, pear), etc.
c. Books in our library can be classified according to the subject, language, the purpose for which you read them, geme, the degree of your preference, etc.