轻型井点用水量Q的计算，主要考虑因素为（）。A.土的渗透性 B.含水层厚度 C.土的

Modern industrial society grants little status to old people. In fact, such a society has a system of built-in obsolescence. There is no formal system for continuing our education throughout our life in order to keep up with rapidly changing knowledge. When our education and job skills have grown obsolete, we are treated exactly like those who have never gained an education or job skills and are not encouraged or given the opportunity to begin anew.
As a society becomes more highly developed, the overall status of older people diminishes. Improved health technology creates a large pool of old people, who compete for jobs with the young. However, economic technology lowers the demand for workers and creates new jobs for which the skills of the aged are obsolete, forcing older people into retirement. At the same time, young people are being educated in the new technology and are keeping pace with rapid changes in knowledge. Finally, urbanization creates age-segregated neighborhoods. Because the old live on fixed incomes, they must often live in inferior housing. All these factors—retirement, obsolete knowledge and skills, inferior standards of living—lower the status of the aged in society.
A century ago, when one could expect to live only to 50 or so, the life span more or less coincided with the occupation and family cycle. But today the average life span allows for fifteen to twenty years of life after these cycles. It appears that our life span is outpacing our usefulness in society.

According to the first paragraph, which of the following is true

A．People don’t have to gain education.

B．People don’t have to learn job skills.

C．People don’t have to be treated as equals.

D．People don’t have chances to begin anew.

为常见外湿证，证见腹痛泄泻，冲击有水音，大便不通，尿少等，属于其（）

A.寒湿停滞证

B.湿困卫表证

C.湿毒侵淫证

D.湿滞经络证

E.湿热蕴结证

（1）要使嫁接的植物体成活，必须使接穗和砧木的______紧密地结合在一起．

（2）保护生物多样性最为有效的措施是建立______．

（3）在肾脏中形成尿液的基本单位是______，神经系统的结构和功能的基本单位是______．

（4）始祖鸟化石的发现说明了鸟类可能起源于古代的______类．

（14分）茶是我国人民喜爱的饮品。某校化学兴趣小组的同学设计以下实验来定性检验茶叶中含有Ca、A1、Fe三种元素。

【资料查询】：草酸铵[(NH₄)₂C₂O₄]属于弱电解质。草酸钙（CaC₂O₄）难溶于水。Ca²⁺、

A1³⁺、Fe³⁺完全沉淀的pH：Ca(OH)₂：pH≥13；A1(OH)₃：pH≥5.5；Fe(OH)₃：pH≥4.1。

试根据上述过程及信息填空：

（1）步骤②加盐酸的作用是                                        。

（2）步骤③操作中用到的玻璃仪器有                                        。

（3）写出步骤⑥中检验Ca²⁺存在的离子方程式                             。

（4）写出沉淀C所含主要物质的化学式                         。

（5）写出步骤⑧中选用A试剂的化学式                  。

（6）步骤⑨的作用是                          ，

猜测步骤⑩的目的是                                                。

速动比率