profesor sana khan PHD in chemistry.i am teaching GCSE chemistry IGCSE chemistry IB chemistry and Olympiad chemistry GRE chemistry college chemistry high school and middle school chemistry i am graduated from USA Oxford university i can speak English chinese cantonese korean Russian African arab urdu Indonesian Malaysia tmail Spanish german French kazakh uzbek kanadian Italian so many languages
profesor sana khan PHD in chemistry.i am teaching GCSE chemistry IGCSE chemistry IB chemistry and Olympiad chemistry GRE chemistry college chemistry high school and middle school chemistry i am graduated from USA Oxford university i can speak English chinese cantonese korean Russian African arab urdu Indonesian Malaysia tmail Spanish german French kazakh uzbek kanadian Italian so many languages
profesor sana khan PHD in chemistry.i am teaching GCSE chemistry IGCSE chemistry IB chemistry and Olympiad chemistry GRE chemistry college chemistry high school and middle school chemistry i am graduated from USA Oxford university i can speak English chinese cantonese korean Russian African arab urdu Indonesian Malaysia tmail Spanish german French kazakh uzbek kanadian Italian so many languages