题目内容：

    Many people experience problems with their spine(脊椎) as they age. The tissue that protects the joints in the spine gradually breaks down. As a consequence, the bones, in the spine begin to rub against each other. This further harms that issue as well as the bones. The result is pain in the joints and, sometimes, in nerves near the spine

This painful problem is actually a disease called osteoporosis. Some people are more at risk of osteoporosis because of genes that they inherited from their ancestors. Extremely heavy people are also more likely to suffer from this disease because their extra weight puts much pressure on their joints. Fortunately, there are steps that people can take to help prevent osteoporosis from developing in their spine.

The most important step is exercise. Stretches can help the muscles around the spine relax and allow bones to shift into better alignment(排列), Strength exercises with light weights or bodyweight exercises like pushups can also help by strengthening the muscles around the spine. However, people should not overdo these exercises as repeated motions can strain the muscles around the spine. Trying to lift heavy weights with poor technique can have the same effect.

Another important factor is diet. It affects the health of spine because many vitamins are necessary for bones and nerves. These include B vitamins and omega-3 fatty acids, all of which helps keep nerves healthy. People can get more B vitamin and omega 3 fatty acids by taking supplements sold by stores. Another important factor is vitamin D. which is essential for strong bones. All of these vitamins and acids can be obtained from food. Thus people can help themselves by including them in their daily diets

1.What does this article mainly explain?

A.Various aspects of a medical condition.

B.The actions of viruses that cause illnesses.

C.Drugs often used to solve the physical issue.

D.The location of organs in the human body.

2.How does the writer begin this article?

A.By predicting improvement.

B.By analyzing a series of data.

C.By introducing minor injuries.

D.By describing a gradual process

3.What can readers find in this article?

A.A warning about working out too hard.

B.A method for improving sleep quality.

C.A slogan used to promote health classes.

D.A big criticism often aimed at doctors.

4.What does the article imply about supplement?

A.They are mainly for youngsters.

B.They are commercial products.

C.They are now being researched.

D.They are seldom truly effective