Analysis of test questions: This question examines students' understanding of the meanings of Mr. De and Mr. Sai in the New Culture Movement. According to what they have learned, Mr. De in Chen Duxiu refers to democracy, Mr. Sai refers to science, and ABC does not meet the meaning of the question. Choose D in this question.

Comments: This question is less difficult. To examine students' ability to remember historical issues, the new culture movement is the basic knowledge in the textbook and the focus of the test proposition. Students can get answers according to the textbook knowledge, which belongs to sub-questions. In addition, students should also master the background, content, significance and evaluation of the New Culture Movement.