The code runs without results

Dear friends in the forum, can you help me see what’s wrong with my code? I have tried many times, but I can’t run the results. I also checked the code carefully, but I couldn’t find the cause of the error. I hope that some kind person can help me see what problems exist in the code. Thank you very much.
kaifang.mod (6.9 KB)

You are missing semi-colons at the end of multiple lines. You are using some variables (such as p_f and p_h) in equations which you haven’t declared as variables.

Thank you very much for your answer. I modified the code according to your prompt, and now there are new problems. Can you help me see how to solve it? Thank you.
kaifang.mod (6.8 KB)