Hearing an explanation of the material will build and expand on what you have read. Keep up with the reading. Once you have fallen behind it is very difficult to catch up. It is expected that you will come to class prepared and that you have read the material in your textbook that will be covered in class that day. Ask questions in class.
Chances are that other people are having trouble with the concept also.
It also helps me determine the level of understanding in the class. Answer questions in class. This will enable you to put your thoughts into words using the scientific language that you have learned. Expressing your thoughts will make for a better understanding of the concepts. If the answer is not perfect, it doesn t matter, it will give me an idea of the level of understanding and give you practice in expressing scientific thought.