Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)

Visitors wear shirts with an image of former Chinese leader Mao Zedong at the Shanghai World Expo site in Shanghai, May 2, 2010. (Photo by Aly Song/Reuters)

Developed for the British American Ambulance Corps, this new motorcycle ambulance is capable of speeding wounded soldiers 90 miles an hour from the front lines to field hospitals. Its springs are synchronized with the patient's heartbeat to avoid increasing fever when traveling over various Terrain. Viewing it in New York August 27, 1941, are left to right: constable Herbert Scott of England, driver; William E. Detlor, whose firm developed the vehicle; M. W. Stand, inspector-general of Civilian Defense, and Maj. Edward Riekert, also. (Photo by AP Photo)

Far from the fancy throngs who gather at the Pebble Beach Concours d'Elegance every year, another collection of car enthusiasts strive to cough up the worst cars imaginable. The Concours d'Lemons gathers the Edsels, Yugos and Azteks of yesteryear to give the freaky and foul their day in the sun. Photo: The 1973 Electra-King three-wheeler, the dead evolutionary branch of today's electric cars. (Photo by Robert Kerian/Yahoo Autos)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Old Heidelberg, Dog with Pipe, 1905. (Photo by Detroit Publishing Company)

American film director Mike Todd and his actress wife Elizabeth Taylor get into a spat after missing their flight from London to Nice on June 22, 1957. (Photo by AP Photo)

This photo taken on February 1, 2018 shows a worker trimming the skin imperfections of a silicone doll at a factory of EXDOLL, a firm based in the northeastern Chinese port city of Dalian. With China facing a massive gender gap and a greying population, a company wants to hook up lonely men and retirees with a new kind of companion: “Smart” sеx dolls that can talk, play music and turn on dishwashers. (Photo by Fred Dufour/AFP Photo)