A police officer stands at a police cordon near the scene of a terror attack in London, U.K., on Sunday, June 4, 2017. A van swerved into Saturday-night crowds on London Bridge, before three men got out and went on a stabbing rampage through nearby bars. (Photo by Luke MacGregor/Bloomberg)

A groundskeeper uses a bamboo broom at Kasumigaike Pond at Kenrokuen Garden in Kanazawa, Japan on January 12, 2016. The japanese garden, located next to Kanazawa Castle, encompasses over 28 acres in downtown Kanazawa. With two ponds, rolling hills with streams and bridges, is considered a strolling-style landscape garden. It's regarded as one of the top three most beautiful gardens in Japan. (Photo by Linda Davidson/The Washington Post)

An Indian artists uses sparkles to decorate statues of the Hindu god Lord Ganesh ahead of the forthcoming Ganesh Chaturthi festival at a workshop in Hyderabad on August 29, 2016. The statues are being prepared for the Ganesh Chaturthi festival a popular eleven-day long Hindu religious festival in India which will be celebrated from September 5 to 15. (Photo by Noah Seelam/AFP Photo)

Baby giraffe of Niger (Giraffa Camelopardalis) “Kenai” (R), born on August 25, 2016, kisses his mother “Dioni” on August 31, 2016 at the zoo of La Fleche, northwestern France. (Photo by Jean-Francois Monier/AFP Photo)

A journalist operate a harness with multiple recording devices capable of recording and live streaming outside the Great Hall of the People where the opening session of the Chinese People's Political Consultative Conference (CPPCC) was held in Beijing, China, Friday, March 3, 2017. Thousands of delegates have gathered at the Chinese capital for the opening of the annual session of the Chinese People's Political Consultative Conference, which advises the rubberstamp parliament, whose annual session begins Sunday. (Photo by Ng Han Guan/AP Photo)

In this September 10, 1977, file photo, from left, Hua Guofeng, Chinese Communist Party (CCP) chairman and Mao Zedong's immediate successor; Ye Jianying, CCP vice chairman and future ceremonial head of state; Deng Xiaoping, no formal titles at the time but soon to emerge as paramount leader during the reform era; Li Xiannian, CCP vice chairman and future president; Wang Dongxing, head of the leadership bodyguard unit who helped topple the Gang of Four, view the body of later Chinese leader Mao Zedong in Beijing. (Photo via AP Photo)

A fledgling solar system containing deep within it enough water vapor to fill all the oceans on Earth five times, located in our Milky Way galaxy about 1,000 light years from Earth in the constellation Perseus. (Photo by Reuters/NASA/JPL-Caltech)

People watch a crocodile with a used motorcycle tyre around its neck on a river in Palu, Central Sulawesi province, Indonesia September 20, 2016 in this picture taken by Antara Foto. Residents suspect the tyre was garbage thrown into the river before it became trapped around the crocodile's neck, reported Antara. (Photo by Mohamad Hamzah/Reuters/Antara Foto)