有闸门和无闸门的溢流坝各有哪些优缺点?
插穗上切口应平截,并离最上面的芽()厘米。 ["0.5~0.8","1.0~1.5","2.0~2.5","2.5~3.0"]
硬枝扦插深度一般落叶树种以地上部露出()个芽或同地表相平为宜。 ["1","2","3","4"]
如何进行溢流坝剖面设计?
新中国成立以来,国家对流落的红军西路军战士给予安臵、抚恤、救济等优抚措施,先后颁发的证件有()。 ["红军流落人员证","退伍红军老战士证","西路军红军老战士光荣证","中国工农红军西路军老战士证","西路红军证"]
泄流单宽流量的选择应考虑哪些因素?