Answer:
Agriculture; Industry; Services.
Step-by-step explanation:
Typically, modern developed countries have gone through three stages in their production process. In these countries, initially, the majority of the population was involved in agriculture. The economy was agriculture-based.
Then in the later stages, the economy moved from agriculture to industries. The majority of the population became involved in industries.
Then finally, the population shifted from industries to the services sector. Most of the population now is involved in the services sector.