16. Antonyms are classified on the basis of ______ opposition. (      )

A. semantic                                                   B. euphemistic

C. idiomatic                                                  D. grammatical

17. Lion，elephant，tiger, turtle，sheep and snake are ______ of animal. (      )

A. hyponyms                                                 B. synonyms

C. collocation                                                D. denomination

18. As far as denotation is concerned，relative synonyms may differ ______.(      )

A. in the diachronic approach                          B. in the stylistic and emotive colouring of words

C. in usage in simple terms                             D. in the range and intensity of meaning

19. Borrowing has caused word-meaning changes，as indicated in“______ formerly meant animal，and later animal from Latin and beast from French found their way into English ______.”(      )

A. deer                                                         B. cattle

C. sheep                                                        D. bird

20. There are generally two major factors that cause changes in meaning，extra-linguistic factors and ______ factors within the language system. (      )

A. functional                                                 B. external

C. meaningful                                                D. internal