Simplify the following text for a Grade 10 native English-speaking person.
Original: Other modern orthographies for Slavic languages eliminated one of the two letters during alphabet reforms of the 19th or 20th centuries : Russian , Macedonian , Serbian and Bulgarian languages use only â Ð â , whereas Belarusian uses only â Ð â .
Simplified: Russian , Macedonian , Serbian and Bulgarian languages use only Ð ; and Church Slavonic and Ukrainian uses both Ð and Ñ -- .