You are using an outdated browser. Please upgrade your browser to improve your experience and security.
Question: Which American inventor introduced a hoe-shaped safety razor with a guard along one edge in 1880?
Answer: In 1880 King Camp Gillette introduced to the market a hoe-shaped safety razor with a guard along one edge.
Question: Which is a method of graphic tracing of the electric current generated by heart muscle during a heartbeat, first developed by Dutch physiologist Willem Einthoven in 1903?
Answer: Electrocardiography is a method of graphic tracing of the electric current generated by heart muscle during a heartbeat, first developed by Dutch physiologist Willem Einthoven in 1903.
Question: Which was the first practical color photography process, introduced in France in 1907 by Auguste and Louis Lumière?
Answer: Autochrome, introduced in France in 1907 by Auguste and Louis Lumière, was the first practical color photography process. It used a color screen (a glass plate covered with grains of starch dyed to act as primary-color filters and black dust that blocked all unfiltered light).
Question: In 1900 who introduced the Brownie, a simple box camera with a removable film container?
Answer: In 1900 George Eastman introduced the Brownie, a simple box camera with a removable film container, which was intended for use by children.
Question: In 1908 Swiss chemist Jacques E. Brandenberger designed a machine for continuous production of which strong transparent film?
Answer: In 1908 Swiss chemist Jacques E. Brandenberger designed a machine for continuous production of a strong transparent film called cellophane.
Question: In 1914 the world’s first two electric traffic lights were installed in which American city?
Answer: In 1914 the world’s first two electric traffic lights were installed at Euclid Avenue and 105th Street in Cleveland, Ohio.
Question: In 1923 which Russian-born American electronic engineer filed a patent for an all-electronic television system, which had cathode-ray tubes for both transmitting and receiving images?
Answer: In 1923 Russian-born American electronic engineer Vladimir Zworykin filed a patent for an all-electronic television system, which had cathode-ray tubes for both transmitting and receiving images.
Question: Which American physicist created a one-step process for developing and printing photographs?
Answer: Edwin Herbert Land created a one-step process for developing and printing photographs.
Question: Which electrostatic dry-copying process, invented by Chester F. Carlson, was used to quickly create reproductions of documents?
Answer: Chester F. Carlson invented xerography, an electrostatic dry-copying process used to quickly create reproductions of documents.
Question: Who invented the first contact lens, made of glass and developed to correct irregular astigmatism, in 1887?
Answer: In 1887 Adolf Fick invented the first contact lens, which was made of glass and developed to correct irregular astigmatism.
Question: In the 1940s Swiss engineer George de Mestral saw tiny hooks on the burrs clinging to his hunting jacket and invented the hook-and-loop fastener system known as what?
Answer: In the 1940s Swiss engineer George de Mestral saw tiny hooks on the burrs clinging to his hunting jacket and invented the hook-and-loop fastener system known as Velcro.
Question: Which diagnostic imaging method uses a low-dose beam of X-rays that crosses the body in a single plane at many different angles?
Answer: A computed tomography scan (CT scan) is a diagnostic imaging method that uses a low-dose beam of X-rays that crosses the body in a single plane at many different angles.
slot แจก เครดิต ฟรี ไม่ ต้อง ฝาก 2020 โรม่าทุน30 win555 เครดิต ฟรี มาเฟีย สล็อต เครดิต ฟรี 188betuytinkhong เล่น สล็อต ฟรี ไม่ ต้อง ฝาก slotxoเติมเงินpubg ดอทมุนเมื่อคืน 8899 casino เครดิต ฟรี jdb168 เครดิต ฟรี
เกมส์ สล็อต เหมือน จริง สล็อต78sport เกม ยิง ปลา สล็อต แอ พ พนัน เงิน จริง เกม slot machine
slotxo วง ล้อ เครดิต ฟรี แค่ สมัคร ล่าสุด เครดิต ฟรี ไม่ ต้อง ฝาก 2019 ไม่ ต้อง แชร์ แจก เครดิต ฟรี 500 ไม่ ต้อง ฝาก 2018 idlinesbobet888
สล็อต555zero ฝาก ถอน ไม่มี ขั้น ต่ํา วอ เลท jokerslotเกมsteam บอลไทยมาเลเซีย เว็บแทงบอลน้ําดี