Generally speaking, the core and key knowledge points are selected for chapter trials.
At the same time, in order to examine various abilities, the content of the trial lecture may be accompanied by experiments (but the experiments will not become complicated because there is no time to prepare). Attention should be paid to the standardization and completion of the experiments, and the experimental phenomena should be clear. At the same time, it emphasizes that the explanation ideas are clear, which is conducive to students' observation.