英语听力精选进阶版 14409（在线收听）

Electronics 'affect bird navigation'

Vocabulary

remarkable

amazing

compass

device to establish position which has a needle always pointing north

mains electricity

system of wires which carries electricity into a house

satnav

system of computers and satellites used to establish location

found their bearings

discovered their exact position in their journey

back-up

device or system kept as a reserve to be used if the main system fails or extra help is needed