洗涤红细胞的适应证为（） A.输注全血或血浆后发生过敏反应的患者 B.自身免疫性溶血

E

Some people have it easy. When their kids ask them what they do at work, they can give a simple, direct answer: “I put out fires” or “I teach primary school”. As a theoretical physicist, I never had this luck. Society has come to expect many things from the physicists. It used to be that we only had to discover the basic laws of the world and supply the techniques that would power the next Silicon Valley. With these expectations we were fairly comfortable: they are the sorts of things we think we know how to do. What makes us uncomfortable and what makes it hard for us to tell our kids what we’re up to is that in this century we have become, though unwillingly, gurus on questions such as “What is the nature of Reality?”

We now deal with a whole new class of problems. We ask how the world began and what the nature of matter is. The answers we are coming up with are just not easy to comprehend for the average person.

So, when physicists get out of their cars in the morning, have a cup of coffee and sit down in front of their computers, they leave a familiar world and enter a place where things act in strange ways that are impossible for ordinary people to understand.

72. According to the passage, in a way physicists are        .

A. honest        B. comfortable    C. strange        D. unlucky

73. By what the writer says about physicists, we know that physicists        .

A. don’t like their careers

B. live in two different worlds

C. are coming up with new answers to old questions

D. don’t have to tell people what they are doing

74. From the passage we can conclude that theoretical physicists        .

A. contributed to the new industry in Silicon Valley

B. only have to answer the basic questions about the world

C. have disappointed the expectations of many people

D. have found it hard to make themselves popular

75. What’s the main idea of the passage?

A. Society seems to know a bit about physicists’ work.

B. Most people are expecting to know what physicists are doing.

C. Physicists are doing more and more difficult jobs.

D. It’s impossible for average people to know physicists’ work.

（1）小军同学在学了常见的盐后，知道家里厨房中有一种盐的溶液能去油污．于是他利用双休日，将这种盐用热水配成浓溶液，将自家的抽油烟机上的油污洗得干干净净．父母高兴，自己也很得意．可是，过了两天，渐渐发现自己的手在脱皮，开始还以为得了什么病，后来一想不是，这是由于自己的疏忽，只考虑了这种盐有利的一面，没有考虑它的另一面．则该同学用的这种盐是______（填化学式），它所说的另一面是指这种盐浓溶液的______性，相信聪明的你在用此盐溶液清洗油污时会采取的措施是______．

（2）碳酸钠和碳酸氢钠是面食加工常用的物质，一定条件下在面团中能产生二氧化碳气体，经过加热后二氧化碳体积膨胀，在面团中留下许多小孔，使蛋糕等面食制品在食用时松软可口，已知碳酸钠加热不能分解，而碳酸氢钠在加热时能发生分解生成碳酸钠、水、二氧化碳．试问无论面团发酵还是没有发酵，要使面团松软可口都应选择______（选填“Na₂CO₃”或“NaHCO₃”），这样做的理由______．

（3）敞口放置在空气中的氢氧化钠溶液，时间久了会变质．有一杯已部分变质的氢氧化钠溶液，其中OH^-与Na⁺的个数比为3：7，则该溶液中另一种阴离子与Na⁺的个数比是______．

有关阿米巴滋养体引起局部组织坏死、溶解病变的特点描述中，哪项是错误的：

A．常引起组织液化坏死，形成溃疡、空洞或脓肿
B．坏死灶周围急性炎症反应明显
C．B和C两项对本病具有诊断价值
D．坏死灶及周围组织内常可见阿米巴滋养体
E．坏死灶边缘不整齐，呈破絮状

肾小球滤过的动力是

A．全身动脉平均压

B．人球小动脉血压

C．人球小动脉血压与出球小动脉血压之差

D．血浆胶体渗透压与囊内压之差

E．有效滤过压

防止锅炉超压的措施有哪些？