A woman walks by flowers in a park in central London, Britain, on March 25, 2021. (Xinhua/Han Yan)

People walk in a park in central London, Britain, on March 25, 2021. (Xinhua/Han Yan)

A squirrel and pigeons are seen on the grass of St James's Park in central London, Britain, on March 25, 2021. (Xinhua/Han Yan)

Photo taken on March 25, 2021 shows flowers blossom in front of Buckingham Palace in central London, Britain. (Xinhua/Han Yan)

People walk by flowers in a park in central London, Britain, on March 25, 2021. (Xinhua/Han Yan)

People walk by flowers in a park in central London, Britain, on March 25, 2021. (Xinhua/Han Yan)