题目内容：

    Voyages of people from England played 1. important part in spreading the English language. At present, English is frequently spoken as an official or common language in many countries. 2.（base）on British English, English spoken in these countries can be understood well by native English speakers. But actually, English has been changing 3. (gradual) in terms of accents, spellings, expressions and vocabulary usage. Because of these facts, you can recognize the differences and tell from which country a foreigner comes.