Tertiary and quaternary industries tend to be ... are all developed in the quaternary sector. In the past, primary and secondary industries were the biggest employers in the United Kingdom.

The tertiary sector includes the selling of ... economically developed countries as tertiary and quaternary industries replace primary and secondary industries. It can be used to prompt discussion ...

Primary agricultural ... nature or from the primary sector. Secondary agricultural goods are treated products and preparations from primary agricultural goods. Together, these form the main definition ...