根据以下资料，回答1~4题。 In 1807 Noah Webster began his greatest work, An American Dictionary of the English Language．In preparing the work, he devoted ten years to the study of English and its relationship to other languages, and seven more years to the writing itself．Published in two volumes in 1828, An American Dictionary of the English Language has become the recognized authority (权威) for usage in the United States．Webster's purpose in writing it was to show that the American language was developing distinct meanings, pronunciations, and spellings from those of British English．He is responsible for advancing simplified spelling forms: 'develop' instead of the British form. 'develop ' 'theater' and 'center' instead of 'theatre' and 'centre' 'color' and 'honor' instead of 'colour' and ' honour '. When was An American Dictionary of the English Language published?