如图7-7-8所示，轻杆的两端分别固定有质量为m和2m的小球a和b，杆可绕其中点

有效循环血量一般不依赖下列哪项（）

A.充足的血容量

B.通畅的微循环

C.有效的心排出量

D.良好的周围血管张力

E.良好的左心功能

下列句子中，没有语病错误的一项是

A．无线信息高速公路具有了" 实时在线""按量计费""快捷登陆""高速传输""自如切换" 的优点正适合大多数移动互联的应用。

B．各级领导干部一定要把改革过程中的暂时困难和应对之策，向广大职工说充分、说清楚，使大家支持改革、理解改革、投身改革。

C．伽利略系统作为新一代全球卫星导航系统，能够给用户提供更加可靠、更加安全、更加精确的卫星导航服务信号，在中国民航、铁路、水运和公路方面，以及移动通讯方面具有广阔的应用前景。

D．我们既拒绝政治观点错误的艺术品，也拒绝只有正确的政治观点，而没有艺术力量的所谓“标点口号式”的倾向。

Where is love How can we find love

The past ages of man have all been carefully labeled by anthropologists. Descriptions like "Paleolithic Man", "Neolithic. Man", etc. , neatly sum up the whole periods. When the time comes for anthropologists to turn their attention to the twentieth century, they will surely choose the label "Legless Man". Histories of the time will go something like this: "in the twentieth century, people forgot how to use their legs. Men and women moved about in cars, buses and trains from a very early age. There were lifts and escalators in all large buildings to prevent people from walking. This situation was forced upon earth dwellers of that time because of miles each day. But the surprising thing is that they didn’t use their legs even when they went on holiday. They built cable railways, ski lifts and roads to the top of every huge mountain. All the beauty spots on earth were marred by the presence of large car parks. "

The future history books might also record that we were deprived of the use of our eyes. In our hurry to get from one place to another, we failed to see anything on the way. Air travel gives you a bird’s eye view of the world—or even less if the wing of the aircraft happens to get in your way. When you travel by car or train a blurred image of the countryside constantly smears the windows. Car drivers, in particular, are forever obsessed with the urge to go on and on: they never want to stop. Is it the lure of the great motorways, or what And as for sea travel, it hardly deserves mention. It is perfectly summed up in the words of the old song: "I joined the navy to see the world, and what did I see I saw the sea." The typical twentieth century traveler is the man who always says, "I’ve been there. " You mention the remotest, most evocative place names in the world like El Dorado, Kabul, Irkutsk and someone is bound to say, "I’ve been there"—meaning, "I drove through it at 100 miles an hour on the way to somewhere else. "

When you travel at high speed, the present means nothing: you live mainly in the future because you spend most of your time looking forward to arriving at some other place. But actual arrival, when it is achieved, is meaningless. You want to move on again. By traveling like this, you suspend all experience; the present ceases to be a reality: you might just as well be dead. The traveler on toot, on the other hand, lives constantly in the present. For him traveling and arriving are one and the same thing: he arrives somewhere with every step he makes. He experiences the present moment with his eyes, his ears and the whole of his body. At the end of his journey he feels a delicious physical weariness. He knows that sound. Satisfying sleep will be his: the just reward of all true travelers.

Anthropologists label nowadays’ men "Legless" because().

A．people forget how to use their legs

B．people prefer cars, buses and trains

C．lifts and escalators prevent people from walking

D．there are a lot of transportation devices

足月新生儿，因胎心率每分钟>160次而以产钳助产，第二产程延长，Apgar评分3分。

若患儿血清胆红素超过342μmol/L（20mg/dl），考虑换血，下列血源何者最理想（）

A.O型血

B.A型血

C.A型血、RhCcDee

D.O型血、RhCcDEe

E.AB型血浆、0型血细胞

步进电动机所使用的电源形式为( )。

A．脉冲电压

B．正弦交流

C．恒定直流

D．以上三种形式均可