hygiene in mutation period

• 变声期保健

hygiene in mutation period的用法和样例：

例句

1. This paper, from the features and affecting factors of this period, presents some viewpoints on vocal music training in the voice changing period.
   通过分析变声期的生理特征以及影响变声的诸方面因素，提出变声期声乐训练的策略和方法。