换发球的英文：
[Sports] change of service

sports是什么意思：
n. 体育运动
v. 故意显示；引人注目地穿戴；嬉戏

sports decisiveness
运动果断性

It was very sporting of you [You were very sporting] to keep it a secret.
你守住该秘密,很有运动员的风度[是承担一定的风险的]。

junior sports development
青少年体育发展

change是什么意思：
n. 变化；交换，交替；零钱
v. 改变；交换，替换；兑换；更换

change a bed;change the baby.
换床单；给婴儿换尿布

We propose 'a change [making a change / to make a change / that a change should be made].
我们建议应做一点改变。

The change of quantity can causes the change of quality.
量变可以引发质变。

service是什么意思：
n. 公共服务系统；公共事业机构；政府机构；帮助，效劳
v. 检修，维修；为…提供服务

overhand service
高手发球

take service with
在￥帮佣

express goods service
特快货运业务