Question

Now, we know that if we do not get enough vitamins, we are at risk of developing a number of diseases. As a result, vitamin supplements（补品），though expensive, are popular with people who worry that they are not getting enough vitamins from the foods they eat. But contrary to what many people think, medical experts have found little evidence that most supplements do anything to improve health or protect against disease.

In fact, medical experts warn that taking too many of some vitamins can be harmful. For example, too much vitamin E can cause bleeding. People should discuss what vitamins they take with their doctors, as some vitamins can produce harmful side effects when mixed with medicines.

Experts, however, say that sometimes vitamins can help prevent disease. People who know they lack a particular vitamin should take vitamin supplements. Some older adults, for example, may not have enough vitamin B-twelve. This is because, as people get older, their body loses its ability to take it from foods. Also, people who spend much time inside may need some extra vitamin D as the skin makes this vitamin from sunlight.

Different vitamins are found in different foods. Vitamin A is found in fish liver oil. It also is in the yellow part of eggs. Sweet potatoes, carrots and other darkly colored fruits and vegetables contain substances that the body can change into vitamin A. Vitamin B-twelve is found in green leafy vegetables and other foods, like fruits. Vitamin K can be found in pork products.

In fact, for most people, a balanced diet can ensure enough of the vitamins our bodies need. So, it is important for us to eat a mixture of foods every day to ensure that we get enough vitamins our bodies need.

1.What is probably talked about before this passage?

A. How many vitamins a person’s body needs.

B. How many vitamins some foods contain.

C. The benefits that vitamins bring to our health.

D. What people should do to stay healthy.

2.Vitamin supplements are popular with people because ________.

A. people mistakenly think that they are good for their health

B. they contain more vitamins than the foods people eat

C. food does not provide enough vitamins people need

D. people fear that a lack of vitamins will lead to disease

3.From the passage, we can learn that medical experts advise people _________.

A. never to take any vitamin supplements

B. to depend only on food for their vitamins

C. not to take any vitamins together with medicines

D. to consult doctors before taking vitamin supplements

4.For people who lack Vitamin B-twelve, they can eat more from _______.

A. sweet potatoes    B. green leafy vegetables

C. pork products    D. eggs

Answer

1.C

2.D

3.D

4.B

【解析】说明文。本文讲述了如今很多人认为多补充维生素能够有效防止疾病，但科学家研究发现，合适的补充维生素能够增强体质，但过多的维生素可能会损害健康，应此我们应该均衡饮食保持健康。

1.主旨大意题。根据文章大意，通篇都在将维生素对人体的作用，即维生素带给我们健康的好处。 if we do not get enough vitamins, we are at risk of developing a number of diseases.如果我们没有足够的维生素，我们可能会生病。故选C.

2.细节理解题。由 if we do not get enough vitamins, we are at risk of developing a number of diseases.可知，人们认为如果没有维生素我们可能会生病。故选D.

3.细节理解题。由People should discuss what vitamins they take with their doctors, as some vitamins can produce harmful side effects when mixed with medicines.知人们在服用维他命时应该咨询医生，已确定对自己的身体是有益还是有害。故选D.

4.细节判断题。由Vitamin B-twelve is found in green leafy vegetables and other foods, like fruits.知，维生素12可以在绿菜或水果中找到。故选B.