1. Friction can be reduced by changing from

2. Galileo's most famous invention was

3. The Relative humidity depends upon

4. Suez canal was nationalized by Egypt on

5. Operation Gibraltar resulted into which war

6. The Shahnama or Book of Kings was written by?

7. The largest part of our hydrosphere is

8. Operation Enduring Freedom (OEF) was conducted by the US in

9. Martin Luther King Jr was assassinated in the age of

10. World Water Day is celebrated every year on

11. For purifying drinking water alum is used

12. The theory that a single dominant power can maintain world peace is called?

13. The United Nations' (UN) International Day of Peace is celebrated on September 21 since

14. Infrared radiations from the Sun are strongly absorbed by?

15. Operation Desert Shield was launched by US in

16. Ozone layer absorbs most of the

17. The latitude 'AA' on the map represents the

18. What material is used to coat iron in the galvanizing process?

19. The self-interest perused by individuals causing collective destruction is called theory of

20. Ecology is the study of