不论测验河段的稳定性及其他条件如何，若在其上下游附近发生堤防决口等意外的破坏水流规律

《标准资格预审文件》组成文件中，适用于公开招标，具有代替招标公告功能的文件是（ ）

A．资格预审公告

B．申请人须知

C．资格审查方法和办法

D．资格预审申请文件

从物质分类的角度，下列人体必需的营养素中，有别于其他物质的是

A．淀粉

B．蛋白质

C．维生素

D．氯化钠

从化学反应基本类型分析，属于置换反应的是  [ ]

A．           

B． 2Mg+O₂2MgO

C．2Al+6HCl→2AlCl₃+3H₂↑           

D．CuSO₄+2NaOHNa₂SO₄+Cu(OH)₂  

You can't imagine _______ when they received these nice Christmas presents. [ ]

A. how they were excited

B. how excited they were

C. how excited were they

D. they were how exited

司可巴比妥溶液的澄清度检查物质是（）.

A．苯丙二酰脲 

B．酸性杂质 

C．2-苯基丁酰胺 

D．对氨基酚 

E．苯基丁酰脲