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问题 选择题
如图所示，把一反射面向上的凹镜置于容器内，有一束平行光线以凹镜反射后会聚在A点，如果向容器内加一些水，将凹镜恰好浸没在水中，则该光束的会聚点A的位置将（　　）

A．向下移动一些

B．保持不变

C．向上移动一些

D．与水的浓度有关，无法判断

答案

答案：A

填空题

气温年较差是指一年中最高                与最低               的差。
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单项选择题

DOM is a platform- and language-(1)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(2).DOM is a (3) -based API to documents, which requires the whole document to be represented in (4)while processing it.A simpler alternative to DOM is the event-based SAX, which can be used to process very large (5) documents that do not fit into the memory available for processing.

空白（2）处应选择（）

A.text

B.Image

C.Page

D.graphic
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