词汇	trail formation
释义	trail formation 纵队队形
随便看	origin and development of the names origin and distribution origin and distribution of nitrogen Origin and domestication origin and evolution Origin and Evolution of Lettuce Origin and Evolution of Life origin and evolution of sex Originate from sth originate from… original works original wort original writ original writer Original writings of celebrated scholars original writing style original yield original yin original YuPian original zoology origin analysis origin and characteristic origin and destination origin and destination survey originating entity