in echelon
短语词组
- official in lower echelon 下级官员
- officials in lower echelon 下级官员
- fly in echelon 梯队飞行
- squadron in echelon 梯次配置的中队
- flying in echelon 成梯队飞行
- fly in echelon formation 梯次编队飞行
- overall enrichment in echelon 梯次综合富集
- aircraft flying in echelon 成梯队飞行的飞机 返回 in echelon