Li Yuming, a local farmer who is interested in scientific invention, works on his unfinished miniature submarine “Xiaguang V” on the outskirts of Wuhan, capital of central China's Hubei province August 24, 2007. “Xiaguang V”, which is 3-metre long, 1.2-metre in height, has a maximum diving depth of 20 metres, and can hold two adults and one child at the same time. The submarine will be used for tour after safety test, local media said. (Photo by Reuters/Stringer)

Zhao Qiang walks across a street in Shenyang, Liaoning province, April 14, 2014. Zhao, a community officer of the China Disabled Persons' Federation, was diagnosed with multiple when he was two, with the resulting tumour affecting the growth of his left leg, his grandmother told local media, citing a doctor's diagnosis. His uncle modified his shoes, fitting them with stools, to allow Zhao to stand and walk. (Photo by Reuters/Stringer)

Two brides kiss during their wedding ceremony to each other at the wedding registry office in St. Petersburg November 7, 2014. The two St. Petersburg women married in the official city ceremony last week, seemingly circumventing Russia's ban on same-s*x marriages. One of the brides was born a man but is undergoing hormone therapy and considers herself a woman. Though her male passport identity ensured the marriage was legal by Russian law, a St. Petersburg lawmaker has vowed to nullify their wedding. (Photo by Reuters/Stringer)

North Korean bodyguards run along a limousine transporting Kim Jong Un upon his arrival in Dong Dang, Vietnam, February 26, 2019. The second meeting of the US President and the North Korean leader, running from 27 to 28 February 2019, focuses on furthering steps towards achieving peace and complete denuclearization of the Korean peninsula. (Photo by Reuters/Stringer)

People look at a man, who residents said was killed by al Qaeda militants, hanging on a bridge in Yemen's southeastern city of Mukalla June 17, 2015. Al Qaeda militants in Yemen killed two alleged Saudi spies, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected U.S. drone strike. (Photo by Reuters/Stringer)

People look at home-made armoured vehicle look-alikes on a street in Shenyang, Liaoning province, November 12, 2014. A man surnamed Zhang and his friends converted two cars into these two vehicles, for his son, and will be displaying them on show at a local park. The cannons on the vehicles can fire paintballs and smoke shells, local media cited Zhang as saying. (Photo by Reuters/Stringer)

A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)

Tong Jieping, 44-year-old mentally disabled patient, is chained by his foot inside his room, in Qunxing village of Wangjiang county, Anhui province, China, July 14, 2015. Tong was diagnosed mentally ill when he was in his 20s. His parents, both in their 70s, could not afford the medical treatments so they had to lock him up in chains to prevent him from running away, according to Tong's family. (Photo by Reuters/Stringer)