单项选择题 Some one has said that a man's history begins about one hundred and fifty years before his birth, or words ______.

单项选择题 A haphazard knowledge of several styles of a language may be worse than useless if we do not know the type of occasion on which each is appropriate or if we do not know when we are sliding from one of another.

单项选择题 Mrs Smith thought her children went to the movies; ______, they went to the zoo.