1.relay的基本意思是“转述,转达”,一般指传达消息、信息等,用作及物动词,可接名词或代词作宾语,还可接双宾语,其间接宾语须由to来引出。
2.relay也可作“转播”解,可指通过卫星、无线电等来传播信息、节目等,用作及物动词,接名词或代词作宾语。
3.relay的过去式和过去分词均为relaid。

relay out(v.+adv.)
发送…; 转播或传送… send out; pass on (sth such as a message received from elsewhere), as by radio, to a distant place or additional people
▲relay sth⇔ out
The church was crowded, so electrical machinery was used to relay the service out to the people.教堂里挤满了人,所以用电子设备把礼拜式转播给外面的人听。

用作及物动词
▲S+～+n./pron.
They will relay your message.他们会转达你的口信。
Messengers will relay your letters.邮递员将接转你的信件。
◇ 用于be ～ed结构
The Sunday Concert will be relayed live on BBC Radio Three.星期日音乐会将通过英国广播公司第三套广播节目转播。
The program is being relayed by satellite.节目正在通过卫星转播。
用作双宾动词
▲S+～+n./pron.+to pron./n.
She relayed the information to us.她向我们转达了那消息。
He relayed a task to subordinate units.他向他的下级单位转达指示。
Could you relay the news to the other teacher?你能将这消息传达给其他教师吗?
This metal tower is used to relay television signals to distant villages which were formerly unable to receive them.这个金属塔是用于向遥远的村子转播电视讯号的,以前那些村子收不到信号。