An important chemical in wine, beer, and hard liquor, ethyl alcohol is a natural substance derived from the fermentation of yeast and sugar. Insofar as it contains calories, ethyl alcohol is a food, but since it affects the central nervous system, it is also a drug. Its presence in alcoholic beverages ranges from a low of 4% (eight proof) in most beers to more than 50% (100 proof plus) in hard liquors. The higher the proof, the higher the calories and the greater the effect on the central nervous system.

Q. Circle the outline which represents the structure of the paragraph and underline the topic sentence: ▼ ▲ ♦ ▊.