How can domain, linking, lookup and weak be used in an e-commerce database? (edited)
domain: entity describing a core business element of the database.
linking: entity used to resolve a many-to-many relationship into two one-to-many relationships.
lookup: entity used to store lookup values and ensure data integrity and consistency.
weak (master/detail): an entity that depends on another entity for its meaning.

Python. primary u. s. interstate highways are numbered 1-99. odd numbers (like the 5 or 95) go north/south, and evens (like the 10 or 90) go east/west. auxiliary highways are numbered 100-999, and service the primary highway indicated by the rightmost two digits. thus, the 405 services the 5, and the 290 services the 90. given a highway number, indicate whether it is a primary or auxiliary highway. if auxiliary, indicate what primary highway it serves. also indicate if the (primary) highway runs north/south or east/west.