Sentence:  The existence of two major literary centres in the First Bulgarian Empire led to the emergence of two <WSD>recensions</WSD> of Old Church Slavonic: the Bulgarian <WSD>Recension</WSD> and the Macedonian <WSD>Recension</WSD>. 
Meaning of the word marked with <WSD> tags:  A family of manuscripts which share similar traits; the variety of a language which is used in such manuscripts.