【正确答案】正确答案：These three terms are often used by sociolinguists to refer to speech varieties, which move on a scale of the national language, dialects and individual ways of communication. The term dialect carries no value judgment and simply refers to a distinct form of a language.(1 point) Regional dialect is a linguistic variety used by people living in a certain geographical region. It has been found that regional dialect boundaries often coincide with geographical barriers such as mountains, rivers, and swamps.(3 points) Social dialect is a variety of a language or a dialect used by people belonging to a particular social class. The speakers of a sociolect usually share a similar socioeconomic status and/or educational background.(3 points) Register is a speech variety used by a particular group of people, usually sharing the same occupation(e. g. doctors, lawyers)or the same interest(e. g. stamp collectors, baseball fans). A particular register often distinguishes itself from other registers by having a number of distinctive words, by using words or phrases in a particular way(e. g. in tennis: deuce, love, tramlines), and sometimes by special grammatical constructions(e.g. legal language).(3 points)

【答案解析】解析：考查社会语言学中地域方言、社会方言和语域的定义。语言变异指语言社团因受各种社会因素影响导致其语言发生变化，也可以指同一内容由于说话者不同、说话目的不同而引起的语言变体。由于地域的原因产生的变异形式叫地域变异，由于社会因素导致的变异叫做社会变异，在传统语言学中被分别称为地域方言和社会方言。语域是特殊人群使用的语言变体，通常指具有相同职业或具有同样爱好的人使用的语言。