請依下文回答第19題至第23題                                                                                                                        I just looked in the mirror, and I saw an overweight woman looking back at me. Who is she? Is that really me? I am sad to say I am one of the many Americans who do not do enough physical activity. Physical activity includes doing things like housework and walking the dog. It also includes doing exercise, such as playing tennis and going to the gym. A government report says that only 1 in 10 Americans does a lot of physical exercise. 3 in 10 Americans do very little and 4 in 10 Americans do no activity at all. I am one of the Americans who do very little physical activity. We have to make more time to work our bodies. Because most Americans don’t do enough physical activity, they are in danger of having health problems. We are gaining weight because of too little physical activity. We also eat too many high-calorie foods. That’s a horrible fact. We really have to get up and get busy! I’m not a couch potato, but my friend Joey is. His idea of exercise is sitting on the sofa, lifting soda cans and potato chips to his mouth while watching other people exercise on TV. I’m not that bad, but I’ve decided Joey and I are going to change.
19What is this passage mainly about?
(A)The crisis of a middle-aged woman.
(B)The importance of physical exercise.
(C)Too many couch potatoes in America.
(D)The danger of having health problems.