The UK has a unitary, democratic parliamentary and constitutional monarchy system.
Further reading:
Parliamentary Democracy.
yes
A cannon.
well its easy only the U.S.A and England use it
The Mercantile System used American colonies to supply England's needs for resources.
the feudal system
They use the metric system: centimeters, kilometers, etc.
Both systems are in use in England (and indeed in Great Britain as a whole). In the past originally only the armed forces used the 24 hour system but now the whole population is aware of it. Some people use the 24 hour clock system and some just use the am/pm system, most people however are adept at using both systems.
England is a country and is unable to use a computer. The people who live in England use a variety of computers including Apple Macintosh and various computers, including Macs, running the Windows operating system. (See links below)
How did the social system in the south differ from the social system in new england?
The class system of England and Europe
Twas Feudalism
Increased use of manure Using the seed drill three-field system