BACKGROUND:The nucleus tractus solitarius(NTS) is one of the key relay stations of various visceral primary afferent information.

背景：脑干孤束核是内脏痛信息向高位脑中枢传递的一个关键的中继站。

youdao

Another firefighter is stationed at a key point to relay messages to the teams above.

CNN: workers

Going forward, the LLCD will play a vital part in NASA's 2017 Laser Communications Relay Demonstration, a key test of laser-based relay comms in future missions.

ENGADGET

He is respected both as an individual 400m runner and a key team member of the 4 x 400m relay.

BBC: Roger Black MBE