Assertion: elf's nation | /r/CapableOf | build military elf transmitters
Facets:
value: to transmit signals
type: PURPOSE
Source sentences:
text: ELF waves can penetrate seawater, which makes them useful in communication with submarines, and a few nations have built military ELF transmitters to transmit signals to their submerged submarines, consisting of huge grounded wire antennas (ground dipoles) 15 - 60 km long driven by transmitters producing megawatts of power.