Teaching Idea of the day. Creating fair tests.
Don't be a lazy educator..be a fair TEACHER and write your own tests.
This way you can be sure that work the student covered is what is on the test. 
Sure, it is easier print out a canned test.
But it is not fair.
Canned tests often stress different points.
For example, a teacher who had a focus on social history would make a different Civil War test than a teacher who had a focus on political history. 
The person who made that canned test may not have had the same focus you gave the students.
You can make your tests as hard as you want. 
As long as you focus them on work YOU have covered with the kids.