Explanation:

Statement 1 is correct. Tropical cyclones originate and intensify over warm tropical oceans. The conditions favourable for the formation and intensification of tropical storms are:

(i) Large sea surface with temperature higher than 27° C

(ii) Presence of the Coriolis force

(iii) Small variations in the vertical wind speed; (iv) A pre-existing weaklow- pressure area or low-level-cyclonic circulation

 (v) Upper divergence above the sea level system.
The energy that intensifies the storm, comes from the condensation process in the towering cumulonimbus clouds, surrounding the centre of the storm. With continuous supply of moisture from the sea, the storm is further strengthened. On reaching the land the moisture supply is cut off and the storm dissipates. The place where a tropical cyclone crosses the coast is called the landfall of the cyclone.

Statement 2 is correct : Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large-scale destruction caused by violent winds, very heavy rainfall and storm surges.

statement 3 is incorrect: The cyclones, which cross 20-degree N latitude generally, recurve and they are more destructive.