钢材按按用途分可分为几类？具体说明其用途。

患者女，23岁。因甲状腺功能亢进施行甲状腺次全切除术，术后24小时突然出现烦躁不安、呕吐。体温39.5℃，脉搏128次/分。 正确的紧急处理措施是（）

A.镇静、吸氧、维持体液平衡

B.给予普萘洛尔

C.冬眠疗法配合物理降温

D.口服复方碘溶液或静脉滴注10%碘化钾

E.以上都是

窝沟封闭的适应证是（）

A.患有较多邻面龋

B.对侧同名牙有龋

C.已充填完好的牙

D.牙萌出4年无龋

E.恒切牙和尖牙

可用于提高坐果率的植物生长调节剂是（）

A.NAA

B.KT-30

C.2，4-D

D.PP333

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.

The high development of economic technology________.

A．makes job skills out of fashion

B．lowers the demand for workers

C．forces old people into retirement

D．creates new jobs for older people

手机银行贴膜卡开卡后，如果换了手机是否可以继续使用？