181. Who is the inventor of the shotgun choke?
Richard Jordan Gatling
Sylvester H. Roper
182. Who invented pasteurization?
183. Who is credited with the discovery of the photovoltaic effect?
Antoine César Becquerel
René Just Haüy
184. Nephoscope was invented by:
Charles A. Doswell III
Leslie R. Lemon
185. Who designed APS underwater rifle?
186. Matthias Schleiden and Theodor Schwann are credited for inventing:
187. The game of carrom is believed to have originated from:
188. Who discovered polystyrene in 1839?
John Wesley Hyatt
189. Which company invented push button phone?
190. Who is the inventor of the frameless parachute?