气割用氧气的纯度一般要求在（）以上。 75%。 85%。 90%。 99.5%。
Which three of these Metro Ethernet services map to E-Line services that are defined by the MEF？ （） Ethernet Private Line。 Ethernet Wire Service。 Ethernet Relay Service。 Ethernet Multipoint Service。 Ethernet Relay Multipoint Service。
原发性饮水
Refer to the exhibit. Which two statements are correct？（） All six routes will be installed in the routing table。 Two routes will be installed in the routing table。 Four routes will be installed in the routing table。 All the routes were redistributed into BGP from an IGP。 All the routes were originated by BGP with the network command。
线槽敷设时，应在（）部位设置吊点或支点。 线槽中间及接头处。 距接线盒1/3m处。 线槽转角或分支处。 直线段不大于4m处。
沙质海岸区建港，防波堤和口门的布置当考虑泥沙淤积时，指出哪个措施是不合适的？（）
