According to the data provided by Zhengzhou Agricultural Products Quality Inspection and Distribution Center, the Ministry of Agriculture conducted sampling inspection on bean sprouts sold in some provinces and cities. First, investigation is one of the commonly used methods of scientific inquiry. First of all, we should make clear the purpose and object of the investigation and make a reasonable investigation plan. Sometimes it is necessary to select some objects as samples because of the large scope of investigation. In the process of investigation, we should record it truthfully. The results of the investigation should be sorted out and analyzed, and sometimes statistics should be made by mathematical methods. There are two kinds of surveys: general survey and sampling survey. In order to understand the problems of bean sprouts, in April, the Ministry of Agriculture sold bean sprouts to some provinces and cities.

B, comparative method is to find out the similarities and differences of research objects through observation and analysis, and it is a basic method to understand things. B error;

C. Observation means that researchers systematically perceive, investigate and describe objective things in a natural state by using their own senses and auxiliary tools according to certain purposes and plans, so as to find and verify scientific conclusions. Mistakes;

D, the experimental method is to use specific instruments and materials, through purposeful and step-by-step experimental operation, observation, recording and analysis, to find or verify scientific conclusions. D error.

So choose one