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问题 单项选择题

VHF收发信机输出端口串接空腔滤波器（腔体）的弊端在于（）。

A.会增加反射功率从而增加电压驻波比VSWR

B.有插入损耗且不能实时更改工作频率

C.会滤除信号中有用信息而产生明显失真

答案

参考答案：B

单项选择题

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．modify

B．changing

C．modifying

D．changed
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单项选择题

路基压实过程中各区段交接处，应互相重叠压实，纵向搭接长度不应小于（）m。

A、1

B、2

C、3
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