单选题
A．alert B．while C．stimulating D．psychological E．moderation F．consumed G．conducted H．clarity I．meditation J．perspective K．shrewd L．eliminating M．functional N．prospects O．contains Coffee can be considered one of nature's greatest gifts. It gives mental and emotional 42 without harmful side effects, and it 43 a wealth of nutrients. Yet, when most people drink coffee, they are not thinking that the beverage is improving their health. In fact, some may even feel a little guilty, since they believe coffee isn't good for you at all. Well, coffee, like anything else, can cause problems if too much is 44 . Moderate consumption of coffee provides your body with a wealth of antioxidants. These substances are responsible for 45 free radicals. They are the chemical byproducts produced any time your body does something. A small number of them can help serve as a buffer against negative elements, if they aren't kept in check, they can cause health problems. Antioxidants ensure that this doesn't happen. The 46 effects of caffeine cannot be ignored either. Not only does caffeine make you more 47 , but it can actually affect your mood. If you were feeling depressed or overwhelmed, a nice cup of coffee could change your 48 . The stack of work that seemed impossible before isn't even a problem now. In addition, caffeine helps stimulate creativity as it speeds up the body's functioning. That's why coffee is often associated with writers and other intellectual professions. Other drugs tend to make people dumber. Consider what happens when people get high off of crack or when they get drunk off of alcohol. They won't be 49 at all. But with coffee, an individual gets a creative boost 50 still helping their bodies. In conclusion, don't feel bad when you're brewing your morning cup of coffee. Unlike a can of soda or a shot of alcohol, coffee will make you feel wonderful while keeping you healthy. Just remember, you do have to consume the beverage in 51 .