11. Which of the following is tropical grassland?

A. Taiga
B. Savannah
C. Pampas
D. Prairies

12. With the disintegration of USSR in end 1991, comprised of ____ Union Republics.

A. 15
B. 10
C. 5
D. 25

13. The iron and steel industries of which of the following countries are almost fully dependent on imported raw materials?

A. Britain
B. Japan
C. Poland
D. Germany

14. The temperature increases rapidly after

A. ionosphere
B. exosphere
C. stratosphere
D. troposphere

15. The humidity of the air depends upon

A. temperature
B. location
C. weather
D. All of the above