Which of the following is TRUE according to the passage?

A．People from the USA and UK both speak English with the same accent.

B．People from the USA and UK both share the same customs and observe the same holidays.

C．People from the USA and the UK speak the same language and have the same culture.

D．Although people from the USA and the UK share the same language, they have huge differences in culture.

文书学的研究是以徐望之的《公牍学史》为开端。