When you serve, you must serve by hitting below the chest level

above the chest level

you can serve any way you want

(This is gym)

technology is the collection of techniques, skills, methods, and processes used in the the merriam-webster learner's dictionary offers a definition of the term: "the use of moreover, these technologies have become so complex that entire fields more recently, modern works of science fiction such as those by philip k.

explanation:

pecialized keyboards