It is a semester test three weeks later

July already began. I feel that time passes early.
A semester test approaches three weeks later but I do not make many measures.
I think that a considerable effort is necessary as for the law , the Britain and the United States culture and the German.
Because German and the Britain and the United States culture's test range is very wide and the law is the class that is the most difficult in the class that I chose.
As measures of the tests of German, I bought a reference book but it is more difficult than a textbook and it is hard.
On the test of the Britain and the United States culture, I aim at high score by reading a lot of textbooks again.
I do not understand how the law should study.
Help me!