You might not think that you could possibly answer these questions with so little exposure to the material, but if you do the preview correctly, you should have some very good general ideas. If you have a general idea of what the passage is about before you really read it, you will be able to understand and remember the passage better.
When you finally get to the point where you are actually slowly reading the passage, read in a "questioning" manner -as if you were seaching for something. It sometimes helps if you take the heading or title of a chapter and turn it into a question.
For example, if the heading of a section in the text is "The Causes of the Civil War", take that title and switch it into a question like: "What are the causes of the Civil War?". Now you have a goal; something to look for; something to find out. When you are goal-oriented, you are more likely to reach the goal. At least you'll remember one thing about the text which you have just read.