换防的英文：
relieve
v. 缓和，减轻；换…的班；调剂；救济；使宽慰；解除职务
- The corporal will relieve the sentry in an hour.
下士一小时后接替卫兵。 - I can not relieve the oppression of the heart.
我难以消除心头的压抑。 - We are all relieved to be back home.
回到家里我们都感到安心了。 - He devoted himself to relieving the distressed.
他献身救助不幸者。 - Money relieved her of material difficulties.
金钱免除了她的经济困难。