first echelon

• 第一梯队

first echelon的用法和样例：

例句

1. After our first echelon was 250 or 300 kilometers ahead, the second and third echelons still had to wipe out enemy troops left behind.
   甚至我们的第一梯队已过去五六百里，第二第三梯队还要消灭被第一梯队甩在后面的敌人。