劳动力人口或劳动力资源人口

原发性帕金森病黑质中最特征性病理表现为（）

A.神经元减少50%，神经元胞质减少

B.多巴胺神经元减少50%，神经元胞质内有Lewy体

C.多巴胺神经元减少20%，神经元变性

D.多巴胺神经元增加，乙酰胆碱神经元减少50%

E.多巴胺神经元增加50%，神经元胞质内有Lewy体

如图所示，两块相同的金属板正对着水平放置，金属板长为L，两板间距离为d。上极板的电势比下极板高U。质量为m、带电量为q的正离子束，沿两板间中心轴线以初速度υ₀进入两板间，最终都能从两板间射出。不计离子重力及离子间相互作用的影响。

（1）求离子在穿过两板的过程中沿垂直金属板方向上移动的距离y；

（2）若在两板间加垂直纸面的匀强磁场，发现离子束恰好沿直线穿过两板，求磁场磁感应强度B的大小和方向；

（3）若增大两板间匀强磁场的强度，发现离子束在穿过两板的过程中沿垂直金属板方向上移动的距离也为y，求离子穿出两板时速度的大小υ。

住宅工程中用于管道熔接连接的工艺参数、（）、施工方法及施工环境条件应能够满足管道工艺特性的要求

A.熔接温度

B.熔接时间

C.熔接速度

D.熔接设备

E.熔接方案

下面哪几项属于计算租金时应考虑的要素（）？

A.租赁物价格

B.租赁物残值

C.租赁期限

D.租赁手续费

Due to a constantly (66) environment, a poor understanding of the user’s needs and preferences, as well as a (67) of willingness to modify (68) organizational structures and decision models, the full economic potential of Web Information Systems (WIS) has not been realized by now. The data object types of the (69) meta model, the Extended World Wide Web Design Technique (eW3DT), provide hypertext designers (70) a conceptual, user-centric framework and graphical notation for the construction of both, (71) and customized models, during the software development (72) of commercial WIS. A reference model as a normative concept represents an abstraction of a (73) company, its functional units, or its (Web) Information System and is intended to streamline the design and implementation of complex applications at (74) costs. As precondition for pursuing a partial globalization strategy, eW3DT (75) between technical and content-specific responsibilities for designing, implementing, and maintaining WIS.

A．gives

B．distinguishes

C．has

D．difference