Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

A humanoid robot named Kansei, meaning “sensibility” in Japanese, makes a facial expression depicting “happiness”, next to the word “Love” during a demonstration at a laboratory of Meiji University's Robot and Science Institute in Kawasaki, south of Tokyo in this June 4, 2007 file photo. Three-fourths of robot installations over the next decade are expected to be concentrated in four areas: transportation equipment, including the automotive sector; computer and electronic products; electrical equipment and machinery. Labor costs have climbed in countries such as China that have been popular for outsourcing production, while technological advances for robots allow them to be more flexible and perform more tasks. (Photo by Yuriko Nakao/Reuters)

In this Sunday, May 29, 2016 photo, fighters take a selfie while firing artillery during fight against Islamic State militants in Fallujah, Iraq. Iraqi forces this week pushed into the city's southern sections after securing surrounding towns and villages more than 50,000 people are believed to be trapped inside the Sunni majority city, about 65 kilometers (40 miles) west of Baghdad. (Photo by Anmar Khalil/AP Photo)

A Humboldt penguin swims in a pool during the annual stock take at ZSL London Zoo in London, Thursday, January 2, 2020. Caring for more than 500 different species, ZSL London Zoo's keepers face the challenging task of tallying up every animal large and small, every mammal, bird, reptile, fish and invertebrate at the Zoo. (Photo by Frank Augstein/AP Photo)

A worker sprays disinfectant as sanitization operations against Coronavirus are carried out in the museum hosted by the Maschio Angioino medieval castle, in Naples, Italy, Tuesday, March 10, 2020. (Photo by Alessandro Pone/LaPresse via AP Photo)

Adult film actress/director Joanna Angel and her husband, adult film actor Small Hands, attend the 2018 Adult Video News Awards at the Hard Rock Hotel & Casino on January 27, 2018 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

Visitors, wearing face masks, enter the Disneyland theme park in Shanghai as it reopened, Monday, May 11, 2020. Visits will be limited initially and must be booked in advance, and the company said it will increase cleaning and require social distancing in lines for the various attractions. (Photo by Sam McNeil/AP Photo)

A disinfection worker wearing protective gear sprays disinfectant to a medical worker after they perform swab tests for the coronavirus disease (COVID-19) during mass test at Islamic boarding school of Sunan Pandanaran on July 29, 2020 in Yogyakarta, Indonesia. Indonesia is struggling to contain hundreds of new daily cases of coronavirus amid easing of rules to allow economic activity to resume, has reported more than 100,000 coronavirus cases and with at least more 4,900 recorded fatalities. (Photo by Ulet Ifansasti/Getty Images)