Final answer:
The effective topic sentence for the given paragraph could be: Ice cream sales are influenced by the popularity of the treat and the designation of July as National Ice Cream Month.
Step-by-step explanation:
The effective topic sentence for the given paragraph could be: Ice cream sales are influenced by the popularity of the treat and the designation of July as National Ice Cream Month.
This topic sentence introduces the main ideas of the paragraph, which are the high sales of ice cream and the designation of July as National Ice Cream Month. It sets the stage for the subsequent sentences that provide supporting information about the popularity of ice cream and its association with warm weather.
By starting with this topic sentence, the paragraph will flow logically and provide a clear focus for the reader.