A~F都是初中化学中的常见物质,且有如图所示转化关系.A能作建筑材料,B能作食品

题型:问答题

问题:

A~F都是初中化学中的常见物质,且有如图所示转化关系.A能作建筑材料,B能作食品干燥剂.

(1)E的化学式为______

(2)A生成B、C 的方程式______

(3)含有较多F的水叫______.

(4)写出A和C、D 生成F的反应方程式______.

考点:物质的鉴别化学反应方程式的书写文字表达式化学式的写法和意义物质的推断
题型:问答题

随着工业和科技的发展,下列变化中正确的是[ ]

A、工业采用的原料种类越来越少

B、工业部门越来越多

C、工业的分布越来越集中

D、工业生产对劳动力数量的投入要求越来越多

题型:问答题

下列关于生态工程的叙述中,错误的是[ ]

A.它是无消耗、多效益的工程

B.追求经济与生态的双赢

C.实现废物资源化的良性循环

D.实现了能量的多级利用

题型:问答题

Wu Yang, CFA, manages individual portfolios for Far East Trust Company. Hu Haiyun, a client, proposes to Wu Yang, "Any year my portfolio achieves at least a 20 percent return before taxes, you and your family can fly to Sanya in Hainan Province in China at my expense and use my condominium during the Spring Festival in February. " While Wu Yang does not inform his employer of the arrangement, he watches Hu Haiyun's portfolio performance intensively throughout the year and makes sure her account gets top priority for any partially executed block trade order. Hu Haiyun's portfolio return exceeds the 20 percent target for the year, and Wu Yang vacations in Sanya during the following February as Hu Haiyun's guest. According to the Standards of Professional Conduct, Wu Yang has least likely violated the CFA Institute Standards relating to:

A. fair dealing.
B. disclosure of conflicts.
C. priority of transactions.

题型:问答题

现代库存控制的关键性突破在于放弃“保证供应”,允许缺货,利用总成本最低来进行决策。( )

题型:问答题

数据管理经过了人工管理、文件系统和【 】3个发展阶段。

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