橡胶安全帽、玻璃钢安全帽的使用期限是（）。A、1个月至3个月 B、30个月至36个月C

By the time you get to Beijing tomorrow, I ______ for Shanghai.

A．am leaving

B．should have left

C．will leave

D．will have left

下列关于贪污贿赂犯罪的说法正确的是（）。

A.贪污贿赂罪的犯罪主体是特殊主体，其包含的所有罪名都只能由国家工作人员构成

B.国家工作人员因挪用公款收受贿赂构成犯罪的，应当实行数罪并罚

C.挪用公款进行非法活动，只有3个月未还的，才构成挪用公款罪

D.受国家机关、国有公司、企业、事业单位、人民团体委托管理国有财产的人员可以成为贪污罪的主体

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.

In the author’s view, the Greeks who studied conic sections（）

A.were mathematicians

B.worked with electricity

C.were interested in navigation

D. were unaware of the value of their studies

主机油箱排烟风机何时启、停？油箱排烟风机与油位有何关系？