Inventions In which decade were the first successful diode and triode vacuum tubes invented? 1900s 1880s 1890s 1800s 1900s 1880s 1890s 1800s ANSWER DOWNLOAD EXAMIANS APP
Inventions Which insurance salesman invented the fountain pen in 1884? George Fountain Charles Kettering Lewis Edson Waterman Sir William Grove George Fountain Charles Kettering Lewis Edson Waterman Sir William Grove ANSWER DOWNLOAD EXAMIANS APP
Inventions In which decade was the first solid state integrated circuit demonstrated? 1970s 1950s 1980s 1960s 1970s 1950s 1980s 1960s ANSWER DOWNLOAD EXAMIANS APP
Inventions Who synthesized the first wholly artificial gene? J.J. Thompson Meghnad Saha Benjamin Franklin Hargobind Khorana J.J. Thompson Meghnad Saha Benjamin Franklin Hargobind Khorana ANSWER DOWNLOAD EXAMIANS APP
Inventions When was the toothbrush invented? 1742 1790 1765 1770 1742 1790 1765 1770 ANSWER DOWNLOAD EXAMIANS APP
Inventions When was the first Lionel trains manufactured? 1890 1920 1901 1944 1890 1920 1901 1944 ANSWER DOWNLOAD EXAMIANS APP
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