conductor
n
1 person who directs the performance of an orchestra, a choir, etc (esp by standing in front of them and gesturing with his arms) (管弦乐队、 合唱团等的)指挥.
2
(a) (Brit) person who collects fares on a bus (公共汽车上的)收票员.
(b) (US) (Brit guard) person in charge of a train (火车上的)乘务员, 列车员(英式英语用guard).
3 substance that conducts heat or electric current 导体(导热或导电的物质)
a `lightning conductor 避雷器
Wood is a poor conductor. 木头是不良导体.