| English thesaurus | |||
| |||
| echo check (ssn) | |||
|
echo : 45 phrases in 15 subjects |
| Acoustics | 8 |
| Antennas and waveguides | 1 |
| Economics | 2 |
| Electronics | 2 |
| Fishery fishing industry | 6 |
| Medical | 1 |
| Microsoft | 1 |
| Oil / petroleum | 2 |
| Piezoelectric crystals | 1 |
| Power lines | 10 |
| Radio | 3 |
| Remote sensing | 3 |
| Sound recording | 2 |
| Telegraphy | 1 |
| Telephony | 2 |