1. Which is longest river in world ?

Answer: Nile, Africa

2. Which is longest railway station ?

Answer: Grand Central Terminal, Chicago(USA).

3. Which is largest continent ?

Answer: Asia

4. Which is the largest sea in the world ?

Answer:

Philippine Sea

5. Which is highest dam in world ?

Answer:

Jinping-I Dam - 305 m (1,001 ft) in China on Yalong river.
Second Highest is Nurek Dam 300 m (980 ft) Tajikistan on Vakhsh river.

6. Where is largest Archipelago ?

Answer: Indonesia

7. Which is the highest waterfall in the world ?

Answer: Angel, Venezuela