Almost all bitcoin trading is done in China. but officially banned now by chinese govt.
Even before trading volumes isn't just can only be found on China, we don't even have statistics on it. But that's one factor of it that the possibility that China has the most trade volume in the bitcoin economy or for the whole crypto market.
But later on after the adoption of Japan and South Korea I'm looking at these two good countries that they are now dominating the volume of trades in the South East Asia but with the other continents, I don't have an idea on what country has the most trade.
Yes it is possible to make bitcoin with twitter. I think all the social media sites are the easy source of earning more and more bitcoins just like signature campaign. As you can make bitcoins in this forum you can also earn bitcoins from twitter.
Twitter is one of the sources of making bitcoin from many other sources. You just need to work and sit in front of your laptop or PC.