our study can be divided into two parts: one is in class and the other is out of class. both of them are important to students. they depend on each other.

　　we must attach importance to after-class what we have learnt in class is very. limited, because only knowledge in textbooks can be acquired. however, we can learn more out of class. a most important thing is that knowledge comes from practice. in the after- class study we can apply out knowledge to practice.

　　just iike after-class study, study in class is also very important. it occupies most of our time. we must pay much attention to it. in-class study and after-class study are closely connected with each other and improve each other.

　　if that's the case, why don't we combine them and study effectively?