1 to 3. The number of cases in the control group and the observation group was 1 3, which was significant. If it is found that the number of qualified control groups is still large, random sampling can be carried out. Meaning refers to the thoughts and truths contained in people or things; The second refers to the content, and the third refers to a good name and reputation; Four-finger movement; Five finger value. The cause, function and value of things.