Answer:
1. textbooks - FROZEN USAGE.
2. elements surround a word which clarify the meaning - CONTEXT.
3. the way in which English is used - USAGE.
4. family and friends - INTIMATE USAGE.
5. friends at a football game - CASUAL USAGE.
6. teachers and employers - FORMAL USAGE.
7. making an appointment - CONFERENCE USAGE.
Step-by-step explanation:
This exercise is meant to match the description to the term as a means to understand the usage of the English language. Language can be used in many ways given the context, to respond accordingly to the situation and the people that are interacting in that precise moment. It is not the same to speak with your friends than to speak with your boss, as it's not the same to read it in a textbook.