Sentence:  <WSD>Literary languages</WSD> have been enriched by dialects and have at the same time assisted the levelling out of dialectical differences which in its turn has contributed to [...]. 
Meaning of the word marked with <WSD> tags:  A language variety used as an institutional norm in a community, opposed to vernacular dialects; a standard language.<ref name=:0>(url=https://books.google.com/books?id=1TtvBAAAQBAJ)</ref><ref>H. Schuster-S̆ewc, "Grammar of the Upper Sorbian Language: Phonology and Morphology", Lincom Europa, 1996, p. 249, (978-3-89586-0591)</ref>