单词	定向聚焦
释义	定向聚焦directional focusing
随便看	manual telegraphy manual telephone manual telephone exchange manual telephone set manual telephone switchboard manual telephone system manual telex service manual temperature control manual test equipment manual testing manual time manual toll recording manual toll switchboard manual toll switching system manual toning control manual tool manual torch manual tracking manual tracking digitizer manual tracking tachometer manual training manual-training room manual train operation manual transfer device manual transfer switch