（）鱼的鳞因富含胶原蛋白、而且味道鲜美，故食用时，可不必去鳞。A.草 B.鲤 C.鲥

青少年自省、自律，必须做到“慎独”，就是在有人监督和无人监督时，都能严格要求自己的行为。下列的行为属于慎独的表现的是[ ]

①考试时，不管有老师监考还是无老师监考，都能做到不抄袭

②独自一个人在教室，不乱翻别人的书包

③独自一人拾得别人的钱包，主动上交给学校，帮助找到失主

④在公共汽车上，不管有没有老师同学在身边，都主动给老人、有困难的人让座

A．①②④

B．①③④

C．①②③④

D．②③④

若关于x的函数f（x）=x²-2ax+2+a有两个零点，

（1）求a的取值范围．

（2）若两零点其中一个在（1，2）内，另一个在（2，3）内，求a的取值范围．

古代医籍中与"紫癜"相似的病名有（）

A.葡萄疫

B.斑疹

C.斑毒

D.丹毒

E.肌衄

阅读理解

     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, do 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

如图表示个体、种群、群落和生态系统间的关系，有关表述正确的是（）

 A．b可表示一个鱼塘中所有的动植物

B．c的结构主要包括垂直结构和水平结构

C．d的主要成分是生产者、消费者和分解者

D．a、b、c、d依次表示生态系统、群落、种群、个体