一导体接在电源电压为6V的电路上，通过导体的电流是0.5A，可知该导体的电阻是

企业采取成本领先战略的目的是成为整个行业中成本最低的制造商。低成本可能并不会减少消费者从产品中获得的价值，通过低成本生产，制造商在价格上可以与行业中的任一制造商竞争，并赚取更高的单位利润。以下情况中，除（），都适用成本领先战略。

A．市场中存在大量的价格敏感用户

B． 产品难以实现差异化

C．购买者不太关注品牌

D．消费者转换成本很高

课外实践活动中，小明同学设计了一个简易的气体温度计，　当温度发生变化时，封闭气体发生热胀冷缩，使水平玻璃管中液柱发生移动，如图所示，瓶塞上面细弯管中有一段液柱。

(1)若周围温度升高时，液柱将向________（填“左”、“右”） 移动。

(2)为了测量温度，小明决定给它标上刻度，请你帮他完成这个任务，说出一种标刻度的具体方法.

胆心反射不会引起（）

A.冠状动脉痉挛

B.心率减慢

C.心律失常

D.血压下降

E.心率加快

该患者有典型的主动脉瓣狭窄三联症，除了呼吸困难，心绞痛外，还包括

A．心悸

B．乏力

C．晕厥

D．咳嗽

E．咯血

阅读理解

     I suppose that having been brought up in the countryside and close  to animals,it wasn't remarkable

(不平常的)when I decided  to become a vet(兽医). Luckily I was also good at all the necessary science

subjects. So after the college entrance examination I found myself at a veterinary college,training to look

after animals in all kinds of situations. I hoped that I would be able to work in the research field so that I

could find cures for animal diseases.

      Much to my surprise,I found public health care was a very important aspect of my course. This is an

area of animal medicine where a vet's work has many things in common with the work of a doctor of

human diseases. I particularly liked it because I recognized that the study of animal diseases can help

human medicine. As we know,many infectious diseases come from animals-including SARS and bird flu.

Some of the infections have only been understood after carefully analytical work in labs by animal doctors. They helped identify the animal source for diseases such as SARS. They were also the first to identify

various kinds of viruses. Sometimes vets are also able to suggest a cure for human illnesses. When I found this out I was determined to make public health medicine my chosen career.

      After graduation,I applied for a job in public health. Soon I found myself concerned with the problem

of bird flu. This is  an illness that attacks birds,but humans can catch the disease  if they are in close

contact with infected birds. Though the job  is dangerous,it makes me proud that vets and other animal  

disease researchers are in the front line helping to fight these  unknown human diseases.

1. The writer wanted to become a vet mainly because______.

A. he did well in all necessary subjects

B. he wanted to help animals

C. he was close to animals in his early life

D. he wanted to find cures for human diseases

2. What made the writer particularly like the course of public health care was that________.

A. it was both important and interesting

B. it could help him connect many human diseases with animals

C. it made a vet's work very much like a doctor's

D. it could help human medicine by studying animal diseases

3. What can be followed if this passage continues?

A. The writer's happy family life.

B. How the writer did research work in studying bird flu.

C. How the writer dealt with the relationship with other workmates.

D. What difficulty the writer met in the research work.

4. Which of the following is implied in the passage?

A. Animals with infectious diseases should be killed.

B. Keeping animals is dangerous to humans.

C. Dangerous as a vet's job is,it is significant to the human race.

D. Animal researchers work in the same way as human doctors.

5. Which of the following statements is NOT true?

A. Being a vet is helpful to both animals and humans.

B. Vets can cure both animals and humans.

C. Vets helped identify animal resources for SARS.

D. Both SARS and bird flu are infectious diseases coming from animals.