题目内容：

    You have probably heard that Japan has among the highest life expectancy(预期寿命) in the world and that the island of Okinawa(冲绳) has the greatest concentration(浓度) of centenarians(百岁老人). But do you know that two-thirds of the centenarians are still functioning independently? That means they are in their own homes, cooking their own meals and living their lives fully - at about 100 years old!

The elders there are less likely than their counterparts in the United States to have heart disease, dementia(痴呆) or certain cancers. Their bones are stronger than those of similarly aged people around the world. Many of these residents are the subjects of one of the largest studies of centenarians ever conducted. Since 1976, nearly a thousand centenarians on the islands have been studied.

More than anything, the Okinawa diet has long captured the headlines. Before knowing what the Okinawans eat, there is a valuable lesson in how they eat.

Remember this term: hara hachi bu. It is translated into English as “Stop eating when you are 80% full.” With hara hachi bu, the philosophy is that you should still be a little hungry when you push the plate away. You are also advised to reduce your portion(食物的分量) sizes, use smaller plates and eat more slowly.

There is a basic biological (生物学的) reason this works. It takes about 20 minutes for the stomach to send signals to the brain that it is full. Unfortunately, most people can shovel down another several hundred calories in that short time. Instead, if you push the plate away and just wait, you will have eaten less and still feel satisfied.

Eating less is associated with longevity, but of course, that also depends on what you eat. Okinawans typically eat seven different fruits and vegetables and 18 different foods a day, and more than 200 different foods and spices regularly in their overall diet.

However, the younger generations are eating more meat and fast food instead of fish and soy. The elderly there are still widely revered(崇敬), but there are fewer of them, and they are less often living to 100 than in decades past.

1.What is the key to the high life expectancy in Okinawa?

A.What they eat B.How they eat

C.Where they live D.When they exercise

2.Which of the following has the closest meaning to the underlined part “shovel down” in Paragraph 5?

A.fill in B.put down

C.fill out D.push away

3.Which of the following statements about Okinawa is true?

A.The elderly are in bad need of mutual respect.

B.There are an increasing number of the elderly.

C.The younger generations have a varied diet.

D.Things are starting to change for the worse.

4.Which could be the best title for the passage?

A.Eat less to live longer.

B.Healthy diets build longevity.

C.The Okinawa: a place of longevity.

D.Improve life expectancy? Slow down.