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. Musical instruments
b. Mobile applications
c. Sports equipment
【正确答案】:a. Musical instruments can be classified based on their main material (woodwind, brass, string), method of sound production (percussion or wind), and musical range (low or high pitch).
b. Mobile applications can be classified according to their function (social media, productivity, entertainment), platform (iOS or Android), and popularity (most downloaded, least downloaded).
c. Sports equipment can be classified based on the sport they are used for (football, basketball, tennis), material (wood, metal, plastic), and size (small, medium, large).