Which statements are true about EIGRP successor routes? （） A successor route is used by EIGRP to forward traffic to a destination.。 Successor routes are saved in the topology table to be used if the primary route fails.。 Successor routes are flagged as "active" in the routing table.。 A successor route may be backed up by a feasible successor route.。 Successor routes are stored in the neighbor table following the discovery process.。
冬季修剪不仅疏枝，还要重短截的树种是（） 毛白杨。 碧桃。 栾树。 龙抓槐。
DNA被称为（）。 脱氧核糖核酸。 核糖核酸。 磷酸。 碱基。
The network administrator must complete the connection between the RTA of the XYZ Company and the service provider. To accomplish this task, which two devices could be installed at the customer site to provide a connection through the local loop to the central office of the provider (Choose two.)（）。 WAN switch。 PVC。 ATM switch。 multiplexer。 CSU/DSU。 modem。
《水利水电土建工程施工合同条件》规定，结清单在（）情况下才生效。 发包人已按最终支付证书支付之后。 承包人撤离工地之后。 履约保函退还承包人之后。 监理人履行监理合同结束之后。 全部退还了保留金。
选出古树防止土壤板结措施（）
