How to get text for default language

I have so tables:

and so data at Language table:

and so data at Text table:

I have to return text for requested language if it exists and text for default language if it does not exist. Is it possible to do that in one query (no while, please)?

Code:

DECLARE @CommentId  bigint = 1--DECLARE @LanguageCode  nvarchar(2) = 'en' -- "english text" returnsDECLARE @LanguageCode  nvarchar(2) = 'ua'   -- nothing at this momentSELECT     t.CommentId    ,t.TextId    ,t.[Text]    ,t.LanguageId    ,RequestedLanguageId = @LanguageCodeFROM dbo.common_Text t     INNER JOIN dbo.common_LanguageType l         ON t.LanguageId = l.LanguageIdWHERE l.Code = @LanguageCode     AND t.CommentId = @CommentId

Thank you.

ADDED:

If code requests a text in 'ua' (ukrainian) and this is no any text for this language, so it is going to search text for russian. if found - ok, if don't it will look for a text for english. List of languages can vary.