相邻两组红外光束感烟探测器光束轴线的水平距离不应()m。A.小于14m B.大于14

广播电台必须经著作权人许可，同时向著作权人支付报酬才可以播放的作品有（）。

A、乙公司出版发行的歌曲集

B、《时尚》杂志上的文章

C、甲刚刚完成尚未发表的小说

D、丙出版社出版的散文集

关于甲、乙、丙三种不含结晶水的化合物的信息如下：

①工业上用电解法冶炼含甲的矿物可得到某种常见的金属单质M，经检测甲是一种高熔点化合物，能溶于强酸、强碱溶液；

②乙是光导纤维的主要成分；

③丙是一种呈深蓝色的碱式盐，将34.6g丙隔绝空气加热分解生成24g黑色固体X、无色酸性气体Y(标准状况下，密度为1.96g/L)和H₂O。生成的Y折合成标准状况下的体积为4.48L。固体X难溶于水，能溶于硫酸，形成蓝色溶液。

试回答下列问题：

(1)组成金属M的元索在周期表中的位置是________。气体Y的结构式为____________，化合物丙的化学式为_______________。

(2)将固体X溶于适量的硫酸，往所得溶液中滴加NaOH浓溶液时，出现蓝色絮状沉淀。写出相关的化学反应方程式：____________________________________。

(3)乙溶于氢氟酸后生成一种极强的二元酸和水。经分析该酸由3种元素组成，其中氟元素的质量分数为79.17%。写出乙溶于氢氟酸反应的离子方程式：____________________________。

(4)工业上常用甲与焦炭、氯气共热生成化合物丁和CO，丁仅由两种元素组成，请写出该反应的化学方程式，并标出电子转移的方向和数目：______________________。

党的十九大报告强调，我们党面临的执政环境是复杂的，影响党的先进性、弱化党的纯洁性的因素也是复杂的，党内存在的（）等突出问题尚未得到根本解决。

A.观念不纯、成分不纯、作风不纯

B.观念不纯、组织不纯、行为不纯

C.思想不纯、党员不纯、行为不纯

D.思想不纯、组织不纯、作风不纯

用户在中文站首页的搜索框里可以直接找到需要的产品，公司，买家，资讯内容。（）

It has often been remarked that the saddest thing about youth is that it is wasted on the young. Reading a recent newspaper report on a survey conducted among college freshmen, I recalled the regret,
"If only I knew then what I know now."
The survey disclosed what I had already suspected from informal polls of students. According to the survey, which was based on the responses of over 188,000 students, today’s traditional-age college freshmen are" more materialistic and less altruistic".
41. ______. It follows then that today the most popular course is not literature or history but accounting. Interest in teaching, social service and the" altruistic" fields is at a low, along with ethnic and women’s studies. On the other hand, enrollment in business programs, engineering and computer science is way up.
42. ______.
Frankly, I’m proud of the young lady (not her attitude but her success). But why can’t we have it both ways Can’t we educate people for life as well as for a career I believe we can. If we’re not, then that is a fault of our educational system--elementary, secondary and higher. In a time of increasing specialization, a time when 90 percent of all the scientists who have ever lived are currently alive, more than ever we need to know what is truly important in life.
43. ______.
Most of us finally come to realize that quality of life is not entirely determined by how much we earn. Sure, everyone wants to be financially comfortable, but we also want to feel that we have a perspective on the world beyond the confines of our occupation; we want to be able to render service to our fellow man and to the world.
44. ______.
It is equally true that, in studying the diverse wisdom of others, we learn how to think. More important, perhaps, education teaches us to see the connections between things, as well as to see beyond our immediate needs.
45. ______.
In the long run that’s what education really ought to be about. And I think it can be. That’s the way it should be. Oscar Wilde had it right when he said that we ought to give our ability to our work but our genius to our lives. Let’s hope our educators answer the students cries for career education, but at the same time, let’s ensure that the students are prepared for the day when they realize their folly. There’s a lot more to life than a job.
[A] Academic emphasis on competition, rationality and externals acknowledges only one kind of knowing. It makes students devalue their inner selves or larger social purposes.
[B] Not surprising in these hard times, the student’s major objective" is to be financially well off." Less important than ever is developing a meaningful philosophy of life.
[C] Education must meet the needs of the human spirit. It must assist students to develop a satisfactory personal philosophy and sense of values; to cultivate tastes for literature, music and the arts; to grow in ability to analyze problems and arrive at thoughtful conclusions.
[D] That’s no surprise either. A friend of mine (a sales representative for a chemical company)was making twice the salary of her college instructors during her first year on the job. And that was four years ago; She must be earning much more now.
[E] Most people, somewhere between the ages of 30 and 50, finally arrive at the inevitable conclusion that they could do more than serving a corporation, a government agency, or whatever.
[F] But the most important argument for a broad education is that in studying the accumulated wisdom of the ages, we improve our moral sense.
[G] While it’s true that we all need a career, preferably a profitable one, it is equally true that our civilization has accumulated an incredible amount of knowledge -- be it scientific or artistic.