which is best to improve our knowledge.reading books or listening the lectures?

It really depends on the person's style of learning. For me, seeing and doing are the best ways I learn. Reading or just listening is too boring for me. I have to see something visual and/or do something with my hands to be able to learn quickly. Like, I remember a lot more stuff I learned from TV from ten years ago compared to something I learned in high school ten years ago. Just because it was visual and more entertaining.

I always listened to the lectures. I found that if I paid attention to teacher and took notes, I was very prepared for testing. With very little studying needed, as I already technically did study when I had listened to the teachers. Books can be useful in helping increasing my understand. However, once I read past a certain point, I find myself skimming. The textbooks are very bland and written in a small font often, which can be very stressful on the eyes and mind.

I like both. When I am interested in a book, I see to it that I will be able to close it accomplished the soonest. In a lecture it depends on the topic and the lecturer. I find both educational in their perfect time and place.