例句與造句

1. Short for Control of Electromagnetic Radiation, it existed from 1951 to 1963 as a way of shifting the broadcast frequencies of AM stations to prevent enemy aircraft from homing in on radio signals for navigation.
2. In 1951, CONELRAD, or Control of Electromagnetic Radiation, became the precursor to EBS . CONELRAD tests required all radio stations to go off the air, except for stations that broadcast over 640 AM and 1240 AM . " That's because we didn't want Russian missiles to home in on any frequencies, " said Ralph Swisher, spokesman for the Federal Emergency Management Agency.
3. It's difficult to find control of electromagnetic radiation in a sentence. 用control of electromagnetic radiation造句挺難的