The author has written this passage in order to tell us ______.

(单选题)54.（ ） (单选题)53.（ ） (单选题)52.（ ） (单选题)51.（ ） (单选题)Phonetics is the study of ______. (单选题)Which of the following is not one of the four maxims of the (单选题)Sometimes, two varieties of a language exist side by side th (单选题)Classification of English speech sounds in terms of manner o (单选题)Captain, My Captain is written for ______. (单选题)______ are not a minimal pair in English.