In which decade of the 20th century did Emile Gagnan and Jacques Cousteau develop and first sell their aqualung now more commonly called Scuba gear ?
The Forties 1940–1949 %6040s 1940s Nineteen-forties 1940s literature '40s 1940-1949 1940's 1940s (decade)
1940 s forties 40s nineteen forties 1940s 1940s decade 1940 1949 6040s 1940–1949 1940s literature
1940s
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1940s