【正确答案】正确答案：Phoneme is the smallest unit of sound in a language which can distinguish two words. For example, the change of the phoneme[t]in the word tin into[d]can change the word into din with a totally different meaning. Therefore, we can say that phoneme is the smallest meaningful unit of sound.(2 points) Morpheme is the smallest unit of language in terms of the relationship between expression and content, a unit that cannot be divided into further smaller units without destroying or drastically changing the meaning, whether it is lexical or grammatical. For example, the word chairman is made up of chair and man. Words like boys, and disappointment can likewise be further analyzed. They are made up of boy and -s, appoint and -ment. These smaller components are known as morphemes. But they themselves cannot be further analyzed.(2 points) As to the correspondence between the two levels of language, there are several occasions. Firstly, a single phoneme may represent a single morpheme, but they are not identical. The phoneme /z/ in the word goes is also the third person singular present tense morpheme, but /z/ occurs very often when it has nothing to do with this specific morpheme. Secondly, morphemes may also be presented by phonological structures other than a single phoneme. They may be monophonemic(dogs), monosyllabic(lovely), or polysyllabic(tobacco). Thus, the syllabic(phonological)structure of a word and its morphemic(morphological)structure do not necessarily correspond. Thirdly, some morphemes have a single form in all contexts, such as dog, cat, but in other instances, a morpheme may have different shapes or phonetic forms. For example, the morpheme that expresses plurality in English may take the forms of -s, -es, -en, in words like maps, watches, oxen and so on.(6 points)

【答案解析】解析：考查音素和语素的意义。音素是语音最小的有区别意义作用的单位，而语素是语法中最小的意义单位。两者在语言层面上存在一定的一致性。一个单一音素可以代表一个单一语素；语素也可以由音系结构而不是单一音素表示；还有一些语素在任何语境中都只有一个形式，如dog，cat等；但其他语素可能受某些限制而有不同的书写形式或语音形式，称为语素变体，如表达复数的语素变体有-s，一es，一en等，它们都是复数语素的语素变体。