The only help for that is to develop better study habits. One thing I should note is that I will not play with dates to test if you are on top of them. They might wonder if perhaps the migration was 25,000 or 35,000 years ago or maybe even 50,000 years ago. I try to make the questions as clear and direct as I can. Of course the questions asking you to pick the main ideas out of a section seem fuzzier than the straight factual questions, which are also on the test.
Students generally do better on questions that test factual knowledge.
If you fail the factual questions, then you have not done even the basic learning. You will either need to study harder or get help. While factual knowledge is the starting point of analysis, there are not a lot of straight factual questions on my tests. It is much more important to recognize the connections between ideas and the significance of historical data. If you answer the questions in the Learning Objectives section of the study guide you will have the data you need for every multiple-choice question that will be on the test.