Many drugs in medicine are artificially synthesized and need to go through many chemical processes to be synthesized. It is conceivable that there must be no mistakes in the process, otherwise it may lead to death. Also, as the drug instructions often say, it should not be mixed with that drug, and its principle is also based on chemistry. It is possible that some components in the two drugs will react, making the drugs ineffective, or the reaction may be counterproductive. Therefore, it is very reasonable for medical students to attend classes.