Why did trade along the silk road flourish during the time of han, kushan , parthian , and roman empire

The silk road flourished because the empires and kingdoms benefited from trade so they protected it and a lot of goods like silk were in high demand in the roman empire because it was considered a luxury  

You can drink laxative, or  do this exercise when you are sitting in the bathroom on the toilet. to relieve  constipation  fast or in about 1 minute, pinch your nose after your usual exhalation. start holding your breath. but do not mouth breath during this just hold your breath.