^That seems like a “duh” moment, but unfortunately a lot of students try to get by with a minimum of effort, expecting to get everything they need from the professor and then blaming the professor for their failures. The textbook is valuable not just because there are questions the prof might ask, but because it spells out the material in different words and examples. The student can ingest it at his own pace, and try to work any examples before looking at the answers. I always got a lot more from my texts than I did from lectures alone.