问题 选择题

现实生活中,尽管轿车的价格有时下降很多,自行车的价格上涨幅度很大,但轿车的价格总是高于自行车的价格。这说明商品价格  [ ]

A.与价值总是保持一致

B.高于商品价值

C.是由供求关系决定的

D.是由价值决定的

答案

答案:D

填空题

化合物V是中药黄芩中的主要活性成分之一,具有抗氧化和抗肿瘤作用。化合物V也可通过下图所示方法合成:

(1)反应①属于           (填反应类型),化合物I中含有的含氧官能团的名称为                 ,化合物V的分子式为                   。

(2)化合物II的合成方法为:

已知合成肉桂酸的反应方程式中,反应物的物质的量之比为1:1,生成物A呈酸性。写出A的一种同分异构体的名称                     。

(3)在一定条件下化合物I和II反应还可以得到一种酯,写出该反应的化学方程式:

                                                                                    

(4)下列关于化合物IV的说法正确的是             (填字母)

A.分子中有三个苯环

B.能发生水解反应

C.使酸性高锰酸钾溶液褪色

D.与三氯化铁溶液发生显色反应(5)肉桂酸有多种同分异构体,写出其中一种同分异构体的结构简式,满足下列条件:

①分子中含有苯环;②可以发生银镜反应;③核磁共振氢谱显示有五种峰

                                                                                                   (只要求写出一种)

单项选择题

Passage Four

Despite a cooling of the economy, high technology companies are still crying out for skilled workers. The Information Technology Association of America projects that more than 800 000 technology jobs will go unfilled next year. The lack of qualified workers poses a huge threat to the U. S. economy.
The most commonly cited reason for this state of affairs is that the country’s agrarian-age education system, separated from the needs of the business world, fails to prepare students in the primary and secondary grades for twenty-first-century work. Yet an inadequate and outmoded education system is only part of the problem. A less tangible but equally powerful cause is an antique classification system that divides the workforce into two camps: white-collar knowledge workers and blue-collar manual laborers.
Blue-collar workers emerged in the United States during the Industrial Age as work migrated from farms to factories. White-collar office workers became a significant class in the twentieth century, outnumbering their blue-collar brethren by mid-century. But the white or blue paradigm has clearly outlived its utility. Corporations increasingly require a new layer of knowledge worker: a highly skilled multi-disciplinarian who combines the mind of the white-collar worker with the hands of the blue-collar employee. Armed with a solid grounding in mathematics and science (physics, chemistry and biology), these "gold-collar" workers--so named for their contributions to their companies and to the economy, as well as for their personal earning ability—apply that knowledge to technology. Of course, the gold-collar worker already exists in a wide range of jobs across a wide range of businesses: think of the maintenance technician who tests and repairs aircraft systems at American Airlines; the network administrator who manages systems and network operations at P&G; the advanced-manufacturing technician at Intel.
But until American business recognizes these people as a new class of worker, one whose collar is neither blue nor white, demands that schools do a better job of preparing employees for the twenty-first-century workforce will be futile. Certainly, polytechnic high schools, colleges, and universities have made heroic efforts to teach workers new skills. But because many people see these initiatives as primarily training blue-collar workers, adequate funds are not invested in such programs, leaving them short of state-of-the-art tools and experienced teachers. And because gold-collar workers need to constantly update their skills to stay current with emerging technology, learning must be a continuous process, one that is funded by companies as well as by taxpayers.

To increase the number of gold-collar workers, ______.

A.the schools should assume the major responsibilities

B.experienced teachers should not be short of current tools

C.the society should consider them as new layer of working classes

D.the taxpayer should pay more money to afford the continuous training