有学者谓，蔡元培主持北京大学前，“全国的出版界，几乎没有什么说得上研究两个字的”。“在之间，北京大学的几种杂志一出，若干种书籍一经印行，而全国的风气，为之幡然一变。从此以后，研究学术的人，才渐有开口的余地。……后生小子，也知道专讲肤浅的记诵，混饭吃的技术，不足以语于学术，而慨然有志...
The compound which does not belong to one carbon unit as follow is. A.-CH3 B.=CH2 C.=CH- D.CO2 查看答案
Later this month a group of elected Gypsy politicians, including members of parliament, mayors and local councilors from all over Europe (OSCE), to discuss how to persuade more Gypsies to get involved in politics. The International Romany Union is probably the most representative of the outfits ...
The electronic configuration of an element X is: 1s 2s 2p6 3s2 3p5 Deduce the atomic number of X To what group does it belong? Give two properties of the group to which the element X belong. Identify element X by name. Write a balanced equation to ...
An organic compound is known to be a carbon-containing compound. An organic compound contains specific functional groups that will dictate or be responsible for the properties and reactivities of the organic compound. It is impor...
amaterials man has got to satisfy his needs 材料供以人员一定满足他的需要 [translate] a采用小组竞赛,引入竞争机制,能使学生更积极地参与到课堂活动,活跃课堂气氛。 Uses the group competition, the introduction competitive system, can cause the student to participate in the classroom activity positively, ...
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Building upon the best practices for evaluating the effectiveness of questionnaires (Kitchenham and Pfieeger, 2002), the questionnaire was evaluated in a pilot study with a group of ten experts within sustainable design and circular economy. The expectations and the purpose of the workshop (i.e...
aMany people burn a lot of fuel in daily life, which is another cause of air pollution. In winter, they burn coal to get warm and in the process, it can produce large amounts of dust, carbon dioxide, carbon monoxide, and other harmful substances polluting the atmosphere. These gases can...
The loss of Arctic sea ice is well ahead of what the Intergovernmental Panel on Climate Change (IPCC) forecast, largely because emissions of carbon dioxide have topped what the panel—which foolishly expected nations to care enough about global warming to do something about it—predicted. “The ...