-
东周时期（公元前8～公元前3世纪）被称为社会制度嬗变、以黄河流域为中心的共同的文化圈、经济圈形成期。下列史实与这一观点相关的是（）
-
用标准齿条型刀具加工ha=1、a=20°的渐开线标准直齿轮时，不发生根切的最少齿数为（）。
-
施工升降机性能试验时，现场风速不应大于（）m/s
-
（）是牙尖交错胎时，上下颌切牙对刃时的咬合关系。
-
A: I've come about your offer for bristles. B: We have the offer ready for you． Let me see..． Here it is． 100 cases of Tsingtao Bristles, 57mm, at..． pounds sterling per kilogram, CIF European Main Ports, for shipment in June, 2009． The offer is valid for three days. A: Why, your price has soared．It's almost 25 % higher than last year's． It would be impossible for us to push any sales at such a price. B: I'm a little surprised to hear you say that． You know very well that market for bristles has gone up a great deal in recent months． The price we offer compares favourably with quotations you can get elsewhere. A: I'm afraid I can't agree with you there． I must point out that your price is higher than some of the quotations we have received from other sources. B: But you must take the quality into consideration． Everyone in the trade knows that China's bristles are of superior quality to those from other countries. A: I agree that yours are of better quality． But there's competition from synthetic products, too． You can't ignore that prices for synthetic bristles haven't changed much over the years. B: There's practically no substitute for bristles for certain uses． That's why demand for natural bristles keeps rising in spite of cheaper synthetic ones． To be frank with you, if it were not for the long-standing relationship between us, we would hardly be willing to make you a firm offer at this price. A: Well, we'll have a lot of difficulties in persuading our clients to buy at this price． But I'll have to try, I suppose.
-
国家鼓励、支持农村使用发展什么能源？
-
分道线
-
甲状腺危象治疗首选（）
-
大使就任须持有
-
有关脱水性质的认识，哪项是错误的（）