A、Hot climate. B、Higher income. C、Diet without vegetables. D、Little attention to exercise. D细节辨认题。对话中男士提到了导致美国人肥胖的几个原因，包括低收入、天气、

W: Mike, why are so many Americans overweight?
M: Well, that’s a good question, Lily. You’d think that with the current fitness craze in the US, there wouldn’t be so many overweight Americans.
W: Just how many people are overweight?
M: (19) About 40% of Americans are overweight. What’s interesting is that one study said that lower-income groups have a higher percentage of being overweight than higher-income groups.
W: Are there any other factors like that in the study?
M: Yes. The study also said that the hotter the climate is, the lower the percentage of fat people is.
W: That makes sense. When it’s hot, you usually don’t feel like eating a lot.
M: Is that why Japanese people are typically skinnier than Americans?
W: Well, our food has less fat and oil than American food does. And Americans eat a lot more meat than we do.
M: You’re right. And we also eat more sugar and junk food. But there’s another reason why so many Americans are fat.
W: What’s that?
M: (20)Nobody works out any more—not even kids. The average American home has the TV on for six hours a day!
W: Wow! No wonder you Americans are so fat. You don’t get enough exercise. Say, Mike, aren’t you getting a little bigger in the waist?
M: Yeah, I guess so.
W: (21)To lose weight, you really need to watch what you eat and get some exercise.
M: Hey, I started a diet and lost ten pounds.
W: So what happened afterwards?
M: (22)1 quit and gained it all back plus five pounds.
19. How many people are overweight in America?
20. Which is a factor for being overweight?
21. What does the woman suggest the man do to lose weight?
22. What happened to the man finally?