( )安装在制动主管的两端,用以开通或关闭主管与软管之间的通路. A. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 截断塞门 B. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 折角塞门 C. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 缓解阀 D. 给风阀