Q1. Fill in the blanks. i. Generally the warm ocean currents originate near .

ii. The ocean bodies and the seas contain water.

iii. The average salinity of the oceans is parts per thousand.

iv. salt is mostly dissolved in ocean and sea water.

v. are formed when winds scrape across the ocean surface.

Q2. True/False

i. When air is heated, it expands, becomes lighter and goes up.

ii. Three-fourth of the earth surface is covered by water.

iii. The low tides also help in fishing.

iv. High tides help in navigation.

Q3. Which is the largest lake in the world?

Q4. What is a terrarium?

Q5. What is meant by the term salinity?

Q6. What is the salinity of Dead Sea?

Q7. How is it possible to float in the Dead Sea?

Q8. Why is the ocean salty?

Q9. What is the effect of high tide?

Q10. What is the effect of low tide?

Q11. What are the major sources of freshwater?

Q12. When is world water day celebrated?

Q13. What is the first indication of a tsunami?

Q14. Why is water essential for our survival?

Q15. What happened to the Indira point during the tsunami of 2004?

Q16. Name one warm ocean current and one cold ocean current?

Q17. What is Tsunami?

Q18. What are ocean currents?

Q19. Where does the word tsunami come from and what does it mean?