I also got 13 - Like Corgito, I didn't even know that we dug canals in this country until the beginning of the Industrial Revolution - I guess the canals that these labourers dug would have been for irrigation?
I also got the one wrong about when English law was first applied to Wales - although, in my defence, I think this is misleading as England invaded, and held, various bits of Wales for various times from shortly after the Norman invasion onwards.
[Don's pedantic hat]
Question 1 is wrong in so much as Wales isn't a country, it's a principality.
Question 2 is wrong as Boudicca fought against the Roman occupation, not the conquest.
Question 3 is wrong, Alfred the Great didn't defeat the Vikings, and he fought them until they accepted the division of the country (Danelaw).
Question 4, the application of English law in Wales, is debatable.
And
Question 6, both Serfs and Yeomen worked the land.
Other than that, it's a perfectly entertaining pub quiz. Personally, I can't see the point of this at all and think it's stupid to bar British nationality to anyone who can't answer these questions. Many Brits wouldn't pass this test and, moreover, does knowing this information really make you a better subject?