In May 22, 2008 , Wonder Girls released single So Hot a decent hit, followed by Nobody a few months later which was one of the most popular songs of the year. Due to a vocal cord injury, Yubin temporarily lip-synched her parts under doctor's orders. The Wonder Girls tour started on February 28, 2009 in Bangkok, Thailand. The Wonder Girls, along with mentor JYP, then held concerts in the United States. In June 2009, Wonder Girls joined with American pop group Jonas Brothers for Jonas Brothers World Tour 2009 as their concerts's opening act. JYP Entertainment announced that "Nobody" would be the first English single, followed by "Tell Me", and that an English album would be forthcoming. It was later revealed that in order to concentrate on their American debut, both Sohee and Sunmi dropped out of high school.