Food web is an important ecological concept ... illustrate energy flow from primary producers to primary consumers (herbivores), and from primary consumers to secondary consumers (carnivores).

Secondary agricultural goods are treated products and preparations from primary agricultural goods. Together, these form the main definition of agricultural goods. Tertiary agricultural goods are ...

There are four main types of industry: primary, secondary, tertiary and quaternary. The type of industry a country specialises in changes over time. There are social, environmental and economic ...

Oil production is separated into three phases: primary, secondary and tertiary, which is also known as Enhanced Oil Recovery (EOR). Primary oil recovery is limited to hydrocarbons that naturally ...