如果长期不练习，语言能力会退化。

Language skills ___atrophy if you don't practice them regularly.

由于缺乏练习，他的钢琴技巧逐渐退化了。

His piano skills ___atrophied due to lack of practice.

长期卧床会导致肌肉萎缩。

Prolonged bed rest can cause muscle ___atrophy.