120型控制阀局减阀由()、局减阀膜板、O形橡胶密封圈、局减阀杆、局减阀簧、压垫、毛毡等组成。 ["局减活塞","缓解阀活塞","主活塞","涨圈"]
()又称专家意见法。 ["头脑风暴法","稽核取向法","德尔菲法","形态分析法"]
压固脱水作用过程中,沉积物的()越来越大,因而产生强大的压力使下面沉积物的体积缩小,孔隙度减少,密度增大。 ["负荷","体积","面积","密度"]
下列属于项目生命周期的阶段是() ["计划","启动","可行性研究","收尾"]
以下哪种是美国对于胶卷感光度的标注方法?() ["DIN","GB","ASA","ISO"]
我国《专利法》第42条规定:发明专利权的期限为()