题目内容：

The global figures reveal that even the Americans put Britain to shame when it comes to taking exercise. Britain has one of the most sedentary populations on the earth, with almost twice the proportion of people defined as “inactive” as in neighboring France. In the UK, 63.3 percent of the population fails to meet recommended levels of physical activity, increasing their risk of conditions such as heart disease, diabetes and cancer. By contrast, 40.5 percent of US citizens are inactive, despite more than 30 percent of them being obese.

Now, there’s good news. Smart foods that tell the brain you have eaten enough could hold the key to beating obesity, researchers have claimed. They hope the foods will contain a special chemical which mimics (模仿) the message our gut (肠道) sends to the brain when it is full. By sending the message earlier, the brain can be fooled into not overeating. “We know nutrients interact with gut cells, which send chemical messengers——hormones —— to the brain to signal ‘stomach full’,” Dr. Jens Holst said.

This message from our food to gut to brain is now being used to fight obesity. Holst discovered GLP­1, which acts on parts of the brain that regulate appetite. “There is a raft of hormones, which will tend to help end a meal,” said Dr. Holst. “We don’t know much about which nutrients are involved and whether we can handle how food interacts with those signaling systems and how those systems are integrated(整合) at different levels in the brain.”

The team hopes their research could lead to drugs which mimic the message, and hopes to eventually make food that can also contain the messages. “It would be even better if we could come up with smart foods,” said Holst.

1.Which of the following is closest in meaning to the underlined word “sedentary” in Paragraph 1?

A. Proud.    B. Inactive.

C. Silent.    D. Energetic.

2.What message could smart foods probably tell the brain?

A. Which food tastes good.

B. When to stop eating.

C. How to get enough nutrition.

D. How to live a healthy life.

3.What can we learn from the passage?

A. Smart foods still have a long way to go.

B. Dr. Holst doesn’t think highly of smart foods.

C. There will be more and more over­weight people.

D. It’s fashionable to stay slim at present.