1, clear and definite: the photos should be clear and definite, and the relevant information can be clearly displayed. Avoid blurred photos.

2, professional and accurate: photos should accurately reflect the content of the lecture, and related to the theme of the lecture. Avoid using irrelevant or misleading photos.

3, true and vivid: photos should truly show the relevant scenes or characters, which can arouse the interest and resonance of the audience. Avoid using photos that are too embellished or false.

4. Appropriate content: The photo content should conform to the theme and objectives of the health education lecture and convey correct information and values. Avoid using inappropriate or conflicting photos.