1.In computing, which key has to be pressed along with the control key to undo an action? 2. What is the natural phenomenon that occurs when precipitation is significantly below normal levels, causing water levels to drop and vegetation to die?

3. At the Olympic Games, dressage, eventing and jumping are the three disciplines of which event?

4. Which town in Nagaland is known to the world for halting the Japanese forces during the Second World War?