Inventions In which decade were the first successful diode and triode vacuum tubes invented? 1900s 1890s 1880s 1800s 1900s 1890s 1880s 1800s ANSWER DOWNLOAD EXAMIANS APP
Inventions Which insurance salesman invented the fountain pen in 1884? Sir William Grove Lewis Edson Waterman Charles Kettering George Fountain Sir William Grove Lewis Edson Waterman Charles Kettering George Fountain ANSWER DOWNLOAD EXAMIANS APP
Inventions Which scientist discovered the radioactive element radium? Isaac Newton Marie Curie Benjamin Franklin Albert Einstein Isaac Newton Marie Curie Benjamin Franklin Albert Einstein ANSWER DOWNLOAD EXAMIANS APP
Inventions When was the toothbrush invented? 1765 1742 1770 1790 1765 1742 1770 1790 ANSWER DOWNLOAD EXAMIANS APP
Inventions What charge card, developed in 1950, was the first to be accepted nationally in the US? Visa MasterCharge Discover Diner's Club Visa MasterCharge Discover Diner's Club ANSWER DOWNLOAD EXAMIANS APP
Inventions What Thomas Davenport invented? Screw propellor Chesterfield Sleeping (railway) car Electric streetcar Screw propellor Chesterfield Sleeping (railway) car Electric streetcar ANSWER DOWNLOAD EXAMIANS APP
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