ST1-600型闸调器螺杆能缩短不能伸长的故障原因是（）。

有关小儿脑和脊髓的发育错误的是（）

A.新生儿脑重已达成人的25%

B.新生儿脑神经细胞数比成人明显少

C.神经髓鞘的形成和发育约在4岁完成

D.婴儿期对各种刺激易于泛化

E.脊髓下端于4岁时上移至第一腰椎水平

一项每年进行的全国性的调查表明，过去30年里高中的高年级学生们对非法药品的使用呈持续明显的下降趋势。 要想从上面描述的调查结果得出结论认为20岁以下的人对非法药物的使用正在下降，下面哪项，如果正确，能提供最多的支持

A．高中的高年级学生们使用非法药品的水平的变化很少与20岁以下的其他人使用非法药品的水平变化相符。

B．在过去，高中的高年级学生一直是最可能使用非法药品和最可能大量使用非法药品的人群。

C．高中的高年级学生使用非法药品的比例与所有的20岁以下的使用非法药品的人的比例非常相似。

D．这项调查显示的下降趋势是特别针对20岁以下的人进行的药物教育计划的结果。

E．比起使用非法药品的人数，被调查者中承认出售过非法药品的人数下降得更快。

阅读理解。

     Jogging has become the most popular individual sport in America. Many theories, even some mystical

ones, have been advanced to explain the popularity of jogging. The plain truth is that jogging is a cheap,

quick and efficient way to maintain physical fitness.

     The most useful sort of exercise is exercise that develops the heart,lungs, and circulatory (血液循环

的)systems. If these systems are fit, the body is ready for almost any sport and for almost any sudden

demand made by work or emergencies. One can train more specifically, as by developing strength for

weight lifting or the ability to run straight ahead for short distances with great power as in football, but

running trains your heart and lungs to deliver oxygen more efficiently to all parts of your body. It is worth

doing that: this sort of exercise is the only kind that can reduce heart disease, the number one cause of

death in America.

     Only one sort of equipment is needed - a pair of good shoes. Physicians advise beginning joggers not

to try to run in tennis or gym shoes. Many design advances have been made in only the last several years

that make a pair of excellent running shoes indispensable (不可缺少的) if a runner wishes to develop as

quickly as possible,with as little chance of injury as possible. A pair of good running shoes will have soft

pads for absorbing shock, as well as slightly built-up heels and full heel cups that will give the knee and

ankle more stability. A wise investment in good shoes will prevent blisters (水泡)and the foot,ankle and

knee injuries and will also enable the wearer to run on paved or soft surfaces. No other special equipment

is needed; you can jog in any clothing you desire, even your street clothes.

     It takes surprisingly little time to develop the ability to run. The American Jogging Association has a

twelve-week program designed to move from a fifteen-minute walk (which almost anyone can manage

who is in reasonable health) to a thirty-minute run. A measure of common sense, a physical examination,

and a planned schedule are all it takes.

1. The main purpose of this passage is to ________.

A. discuss jogging as a physical fitness program        

B. describe the type of clothing needed for jogging

C. provide scientific evidence of the benefits of jogging

D. launch a worldwide physical fitness campaign

2. The most effective kind of exercise should be the one that ________.

A. trains the body for weight lifting                  

B. enables a person to run straight ahead

C. is both beneficial and inexpensive                

D. develops the heart, lungs, and circulatory systems

3. What can we learn from the third paragraph?

A. For beginning joggers, tennis or gym shoes are better choices.

B. A pair of good running shoes is necessary for a runner to develop quickly.

C. A pair of good running shoes with a full heel-cup is designed to prevent shock.

D. Comfortable pads will give the knees and ankles more stability.

4. The author's attitude towards jogging is ________.

A. doubtful

B. critical    

C. approving     

D. negative

患者，男，30岁。剧烈运动后胸部疼痛，吸气时明显，胸部X线摄片检查示：左肺野外带可见条带状无肺纹理区，肺组织受压缩小。首先应考虑的诊断是（）

A.左侧气胸

B.左侧肺气肿

C.左肺癌

D.左肺肺炎

E.肺挫伤