我国一般建筑物屋顶材料，首先应综合满足下列哪一组要求（） A. 经济、美观、实用 B

存在需求弹性的情况下，价格增加会导致（）

A．边际收益减少

B．全部收益减少

C．全部收益增加

D．边际和全部收益减少

会计职业道德的内容之一，就是要“坚持准则”，这里的“准则”包括（）。

A.会计法律

B.会计法规

C.会计制度

D.会计准则

Jake’s son Simon, aged 16, wished to buy a particular hi-fi system which had just been launched on the market. He decided to save up some more money and purchase it during the coming months. Jake decided to surprise his son and bought a system from Martin. Martin assured Jake this was the latest model. However, much to Simon’s dismay the model his father purchased was the 2008 model.Required:

(b) Explain whether it is possible for Jake to claim invalidity of contract and on what grounds. (6 marks)

常用提取溶剂极性由大到小的排列顺。序为

A．水＞乙醇＞丙酮＞甲醇＞乙酸乙酯＞正丁醇
B．水＞甲醇＞丙酮＞乙醇＞乙酸乙酯＞氯仿
C．水＞乙醇＞丙酮＞甲醇＞乙醚＞乙酸乙酯
D．水＞甲醇＞乙醇＞丙酮＞乙酸乙酯＞乙醚
E．水＞乙酸乙酯＞丙酮＞甲醇＞乙醇＞正丁醇

配属两台以上调车机的车站，为减少作业干扰，保证作业安全，对每台调车机和调车组所规定的固定作业区域，称为（）。

A.调车区

B.调车场

C.作业区

D.固定区