这个培训计划分为五个等级,每个等级都有明确的学习目标。

The training program follows a five-level ___scale with clear objectives for each stage.

消防员迅速爬上梯子去营救被困在屋顶的人。

The firefighter quickly climbed the ___ladder to rescue the person trapped on the roof.

他正在学习如何唱准音阶中的每个音符。

He is learning how to sing each note in the ___scale correctly.