Theresa May (R) leaves with her husband after giving a farewell speech outside 10 Downing Street in London, Britain, July 24, 2019. Newly-elected Conservative Party leader Boris Johnson took office as the British prime minister on Wednesday amid the rising uncertainties of Brexit. The latest development came after Theresa May formally stepped down as the leader of the country and Johnson was invited by the Queen to form the government. (Photo by Alberto Pezzali/Xinhua)