Common Core testing. . .

The middle school started the common core testing yesterday.  I asked my oldest how things went, he was not very happy.  This kid routinely does very well on tests.  He drives me nuts because he does not study and prepare ahead of time.  I have tried to tell him he needs to start actually opening a book and studying but he insist he knows the information.  He has done well thus far so I really cannot punish him for not studying.  I asked him why he was upset about the test.  He said it was mostly on government.  Now this is a new test for our area.  This is the first year we have used the common core curriculum and supposedly this test grade is going to go toward their end of year grade in this course.  This was his Social Studies test he took yesterday.  I have seen the work they completed in class and some of the tests they have taken this year and I have to say I do not remember seeing anything on government.  He said they spent maybe a couple of days on government.  The work I have seen has been on Africa, Asia, and their government and geography.  I guess my question is how can you hod a student accountable for information that was not taught?  I don't always believe my kids when they tell me they did or did not go over something in class because I know my kids have a selective memory.   Kids also seem to stretch the truth in their favor too.  I am just curious what others have to say about this test.  I would love to know your thoughts.