Final answer:
North America, Europe, Asia, and Africa are the four areas of the world that contain great population clusters.
Step-by-step explanation:
The four areas of the world that contain great population clusters are North America, Europe, Asia, and Africa. These regions have large population centers and high urbanization. Examples of population clusters include the megalopolis in the northeastern United States, the coastal region of Nigeria in West Africa, and the island of Java in Indonesia.