[email secured] Thank you very much! I'm away right now, so I will get back to you by e mail as quickly as possible Chu?n b? du h?c: B?n d?ch ???c ch?ng nh?n có th? lo?i b? rào c?n ngôn ng? nh? th? nào ?? t?n d?ng t?i ?a n?n t?ng này, ít nh?t b