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问题 选择题

下列有关现在的长式元素周期表的判断中正确的是（　　）

A．从左向右数第七纵行是ⅦA族

B．从左向右数第十一纵行是ⅠB族

C．ⅠA族全部是金属元素

D．ⅦA族的全部元素只能表现非金属的性质

答案

A．从左向右数第七纵行是ⅦB族，故A错误；

B．从左向右数第十一纵行是ⅠB族，故B正确；

C．ⅠA族为碱金属元素和H元素，故C错误；

D．ⅦA族从上到下非金属性在减弱，金属性在增强，则原子序数较大的表现出一定的金属性，故D错误；

故选B．

单项选择题 共用题干题

Estimating schedule activity costs involves developing an (1) of the cost of theresources needed to complete each schedule activity. Cost estimating includes identifying and considering various costing alternatives. for example, in most application areas, additionalwork during a design phase is widely held to have the potential for reducing the cost of the execution phase and product operations. the cost estimating process considers whether the expected savings can offset the cost of the additional design work. cost estimates are generally expressed in units of (2) to facilitate comparisons both within and across projects.the (3) describes important information about project requirement that is considered during cost estimating.

空白（3）处填（）

A.project scope statement

B.statement of work

C.project management plan

D.projectpolicy
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单项选择题

对材料制作信息选择主要依据传播目标和目标人群对信息的（）

A.了解情况

B.反馈情况

C.需求情况

D.熟悉情况

E.知情情况
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