下列能使植物茎不断长粗的结构是: A.导管 B.木质部 C.形成层 D.韧皮部

题型:选择题

问题:

下列能使植物茎不断长粗的结构是:

A.导管

B.木质部

C.形成层

D.韧皮部

考点:枝条的发育根的生长探究实验:根生长最快的部分植株生长需要的营养物质
题型:选择题

保证数据的完整性就是

A.保证因特网上传送的数据信息不被第三方监视和窃取

B.保证因特网上传送的数据信息不被篡改

C.保证电子商务交易各方的真实身份

D.保证发送方不能抵赖曾经发送过某数据信息

题型:选择题

处方中a.q.d.是指( )。

A.每小时
B.每日
C.每日2次
D.每日3次
E.每日4次

题型:选择题

踢出去的足球在空中飞行时,受到________力的作用(不计空气阻力),若飞行过程中,所有力都同时消失,足球将________________________。

题型:选择题

For me, scientific knowledge is divided into mathematical sciences, natural sciences or sciences dealing with the natural world (physical and biological sciences), and sciences dealing with mankind (psychology, sociology, all the sciences of cultural achievements. every kind of historical knowledge).

Apart from these sciences is philosophy, about which we will talk later. In the first place, all this is pure or theoretical knowledge, sought only for the purpose of understanding, in order to fulfill the need to understand that is intrinsic and con-substantial to man. What distinguishes man from animals is that he knows and needs to know. If man did not know that the world existed, and that the world was of a certain kind, that he was in the world and that he himself was of a certain kind, he wouldn’t be man. The technical aspects or applications of knowledge are equally necessary for man and are of the greatest importance, because they also contribute to defining him as man and permit him to pursue a life increasingly more truly human.

But even while enjoying the results of technical progress, man must defend the primacy and autonomy of pure knowledge. Knowledge sought directly for its practical applications will have immediate and foreseeable success, but not the kind of important result whose revolutionary scope is for the most part unforeseen, except by the imagination of the Utopians. Let me recall a well-known example. If the Greek mathematicians had not applied themselves to the investigation of conic section zealously and without the least suspicion that it might someday be useful, it would not have been possible centuries later to navigate far from shore. The first men to study the nature of electricity could not imagine that their experiments, carried on because of mere intellectual curiosity, would eventually lead to modern electrical technology, without which we can scarcely conceive of contemporary life.

Pure knowledge is valuable for its own sake, because the human spirit cannot resign itself to ignorance. Butt in addition, it is the foundation for practical results that would not have been reached if this knowledge had not been sought disinterestedly.

The title which best expresses the idea of this text is()

A. Progress in Pure Science

B. Learning for Its Own Sake

C. Man’s Science and Inventions

D. Difference between Science and Technology

题型:选择题

物种货物运价实行在整批(或零担)货物基本运价的基础上加成计价。其中二级危险货物在整批(或零担)货物基本运价基本上,加成( )

A.20%——40%
B.40%——60%
C.60%——80%
D.80%——100%

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