L Sarita Devi, MC Mary Kom, Ritu Grewal and Lovlina Borgohain are assured of medals in the 13th International Silesian Boxing Championship for women in Gliwice, Poland. All the four Indians have advanced to the semi-finals.   Sarita defeated Czech Republic's Alena Czechy 5-0 on Wednesday after going past Kazakhstan's Aizan Khojabekova in the opening round of the 60kg category the day before. Sarita will now square off against another Kazakh, Karina Ibragimova, in the semifinal...