如果当前处理的图像有多个图层，执行“图像-调整-去色”命令对（）图层有效。 ["A.所有图层","B.背景图层","C.除文字层外的其他所有图层","D.当前选择的图层"]
政府的职能体系分为（） ["政府的基本职能","政府的运行职能","政治职能","经济职能","决策职能"]
烧结生产中为什么加入部分白云石粉？
政府职能的特征有（） ["公共性","共同性","法定性","执行性与强制性","差异性与动态性"]
A built-up exhaust valve is one in which （）. ["the stem and heads are made of different material","low-alloy steel is used throughout","a replaceable valve disk is welded to the head","the self-centering action comes from motion of the valve stem in the guide"]
简述高等学校教学过程的特点？
