What are the major post-1950 migration flows. Stream 1:
Stream 2:
Stream 3:
Stream 4:
Stream 5:
Stream 6:

What is the result of the greenhouse effect? a. heat is deflected from the atmosphere. b. heat is released from the atmosphere. c. heat is kept in the atmosphere. d. plants are able to grow in the tropics where the air is the heaviest.

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

Why is terracing used in southeast asian agriculture?