Fonts problem

I have a couple of question about my wordpress theme. I hope somebody can help me
1) It seems that the theme doesn’t support Russian language for some reason. When I try to create a new menu page or insert a widget and type the name in russian, it doesnt appear on a site, but when I do the same but in english letters it works perfectly. IS there anyway to fix that?
2) When I inseert <!–more–> in my text it shows as “Continue reading »”, is there anyway to rename it? (I want to translate it to Russian)
Thank you for the help