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问题 计算题

先化简再求值：[ （x+2y ）（x-2y ）- （x+4y ）2]÷（4y），其中x=5 ，y=2 ．

答案

解：原式=-3y-2x.

当x=5,y=2 时.  原式=-16.

单项选择题

对勘察、设计单位的管理水平，重点考查( )。

A．是否达到了与其资质等级相应的要求水平

B．是否具备相应的人员数量

C．是否具备相应的设备装备

D．是否承接了相应的工程类别
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单项选择题

DOM is a platform- and language- （） API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents (currently, definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented （） . DOM is a （） -based API to documents, which requires the whole document to be represented in （） while processing it. A simpler alternative to DOM is the event-based SAX, which can be used to process very large （） documents that do not fit into the memory available for processing.

which can be used to process very large （） documents that do not fit into the memory available for processing.

A．XML

B．HTML

C．script

D．Web
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