现用焦化分馏塔有（）回流A、汽油回流； B、柴油回流； C、蜡油回流； D、塔底回流

某物流服务项目采用即时配送方式，要求运输方式机动灵活，实现“门到门”直达服务，该项目宜选择（）运输方式。

A．铁路

B．航空

C．管道

D．公路

为了认识酶作用的特性，以体积分数为3%的H₂O₂溶液为反应底物进行的一组实验结果见下表。通过分析实验结果，从表中可得到的实验结论是

①从化学本质看，酶是蛋白质或RNA ②从催化活性看，酶变性后就失去活性 ③从催化底物范围看，酶有专一性 ④从催化反应效率看，酶有高效性

A．①②

B．②③

C．②④

D．②③④

Salomon & Co (Lesotho) Ltd is a small company consisting of Salomon, his sons and his brother. Salomon is the managing director and a principal shareholder. Their sole business is to manufacture shoes and boots. Their principal customer takes about 60% of their sales. Due to economic recession, their principal customer decided to switch their order to a cheaper supplier. As a result, Salomon & Co (Lesotho) Ltd are now teetering on the brink of insolvency. The creditors are threatening to put the company into liquidation.Required:Advise Salomon. (10 marks)

“阳光模式”包括（）项因素和（）大要素.（）

A.4；6

B.6；4

C.6；3

D.4；3

据魏国李悝《尽地力之教》载：“治田勤谨，则亩益（增产）三斗。不勤，则损（减产）亦如之。”又据《孟子·梁惠王上》载：“五亩之宅，树之以桑，五十者可以衣帛矣。”上述材料反映的历史现象是（）

A.井田制开始瓦解

B.小农经济的兴起

C.商品经济的发展

D.家庭手工业产生