Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
나는 공부하는 동안 잡념이 많아서 집중하기 어려웠다.naneun gongbuhaneun dongan jabnyeomi manhaseo jipjunghagi eoryeowotda.I had many distracting thoughts while studying, making it hard to concentrate.