The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Of course a scale of styles exists in all our use of English. Each of us works not just with one English but with many Englishes, and the wider the range of our life and the more various the contacts we have, the wider and suppler must be our command over a range of English styles, each of which we know how to use consistently. A haphazard knowledge of several styles 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 to another. 

There exist a range of （）in the use of English.