text: Many virtual currency projects advertised as "free" have appeared in Vietnam recently?
classes:  No, bitcoin is a cryptocurrency that was invented in 2008 and launched in January 2009.  Besides, bitcoin is a cryptocurrency that was invented in 2008 and launched in January 2009.  Yes, bitcoin is a cryptocurrency that was invented in 2008 and launched in January 2009.  Meanwhile, bitcoin is a cryptocurrency that was invented in 2008 and launched in January 2009.