Also, we don't discuss between students and professor during class. Usually professor gives lecture. We can ask questions, but it cannot be critical. If someone asks critical question, he's going to be in trouble. But here it's very different.
Many professors prefer critical questions, critical analysis.
I had a little trouble with that. In one of my classes, the assignment was write a critical response to one book. Professor felt my reaction was so mild. It is really uncomfortable to me. Different cultural customs.