多项选择题
A.划出开孔接管的四条中心线B.接管内伸余量割去C.压紧垫板使其与筒壁贴紧D.划出开孔的切割线
A.端面不平B.对口错变量C.直线度D.对口间隙
A.firewall-cmd-query-port=80/tcpB.firewall-cmd-add-port=80/tcpC.systemctl enable httpd.serviceD.systemctl is-enabled httpd.servie