Mark 21 torpedo
{'<entity_0>': 'Westinghouse Electric', '<entity_1>': 'Mark 21 torpedo'}
[['Mark 21 torpedo', 'designed by', 'Westinghouse Electric']]
The <entity_1>, designated Mark 21 Mod 0 was a passive acoustic homing torpedo designed in 1943 by <entity_0>.
['anti-surface warfare']