A. It has a long history and is the birthplace of mankind.

B: They are all areas with early industrial development, developed economy and good natural conditions.

C. They all belong to tropical areas with good hydrothermal conditions.

D. High natural population growth rate

Answer: b

1. climatic reasons. Located at the junction of subtropical zone and temperate zone, it is sunny, humid and rainy, rich in water resources and rich in products.

There is a big river passing by.

3. Located on the plain

4. The place where civilization originated (ancient Roman civilization) and the place where people migrated (America).

The eastern part of North America was developed earlier, with good social and economic conditions, convenient transportation and good natural conditions. In the west are the coastal mountains, the Sierra Nevada and the Rocky Mountains. The population growth in North America is mechanized, mainly immigrants, while immigrants are mainly European immigrants, and most of them settle in the east, so the population in the east of North America is dense.

The reasons for the dense population in Europe are: good economic conditions, early development history, the origin of industrial revolution, convenient transportation, advanced technology and high consumption level. In short, it is related to population location;

Natural conditions are suitable, the terrain is mainly plain, deeply influenced by temperate maritime climate, and animal husbandry is developed.