Inventions and Discoveries

96. Who invented the first successful jet engine?
a) Frank Whittle
b) Hans von Ohain
c) Igor Sikorsky
d) Charles Lindbergh

97. Who discovered the law of gravitation?
a) Isaac Newton
b) Galileo Galilei
c) Johannes Kepler
d) Albert Einstein

98. Who invented the first practical telephone?
a) Alexander Graham Bell
b) Elisha Gray
c) Antonio Meucci
d) Thomas Edison

99. Who discovered the principle of electromagnetic waves?
a) James Clerk Maxwell
b) Heinrich Hertz
c) Michael Faraday
d) Albert Einstein

100. Who invented the first practical typewriter?
a) Christopher Latham Sholes
b) Samuel Morse
c) Alexander Graham Bell
d) Thomas Edison