A、Above 50%. B、About 25%. C、Around 68%. D、Approximately 94%. B原文说到有一半以上的美国成年人超重，且大概25％的儿童也如此(so do about twenty-fivepercent of o

Good morning, everyone. Today’s topic is fast food. For many people in other countries, fast food equals American food. All Germans eat sausages, all Chinese eat rice, and all Americans eat hamburgers, right? Well, urn, actually, we do eat a lot of hamburgers. In fact, the average American eats three hamburgers a week, along with four orders of French fries. I’ll tell you, my son is not average, because he’d eat three hamburgers a day, if I’d let him. And I think he eats four orders of French fries by Wednesday. But, even though we still eat hamburgers, did you know that we eat less now than we used to when I was your age? In 1976, we ate 94 pounds of beef per person each year. These days, we eat 68 pounds per person. From 94 to 68, that’s quite a reduction! But just because we eat fewer hamburgers does not mean we eat less fast food. As a matter of fact we eat more fast food than ever. Here is some food for thought In 1970, Americans spent six billion dollars a year on fast food. By 2001, that number had increased to one hundred and ten billioa Six billion to a hundred and ten billion in 30 years! Man, if my stocks had done that well, I wouldn’t be standing here teaching, I’d be in my private Lear jet on my way to Hawaii!
    It’s not surprising that we spend more on food than entertainment. After all, we have to eat. But Americans spend more money not just on food, but on fast food. Is this healthy? Um, probably not. Maybe you’ve noticed that Americans are getting fatter. And I don’t mean just a little plump. We’re getting obese. America has the largest percentage of obese people among all developed nations. Did you know that more than half of all US adults weigh too much? So do about twenty-five percent of our children. The US surgeon general calls this a crisis. A crisis! Think of it like a river. It keeps raining, and the river keeps rising. At first no one is very worried. But the water keeps rising, and rising. Then it overflows its banks and floods the city. Suddenly, we have a crisis. Why is being obese a crisis? Well, for one thing, it’s killing us. Obesity —um, being too fat—increases the stress on our bodies. Our hearts and other organs have to work harder, and they break down sooner. Obesity is the number two cause of death in America today, right behind smoking. We all know how bad smoking is. Being too fat is the second-biggest killer.
20. What does the speaker say about fast food consumption in America?
21. What’s the percentage of American children who are overweight?
22. What do we know about obesity from the lecture?