Task: Question Answering
Input (English): Context: I might add that Bunni got a kick out of Jeep drivers tipping their hands or waving at each other . See all the old cars ? Can you hear and smell the craziness ? There were lots of Harleys and motorcycles lining the streets , too . 
Question: What may be the reason for strangers waving at each other ?
Output (English): Because of their similar interest .