Xiao Min wrote in his diary: "Li Ming is very popular with female students because of his good academic performance and handsome appearance. But as soon as I saw him with another girl, I was puzzled.

C

Test analysis: Xiaoli in the material has a good impression on boys, which is a normal psychological phenomenon in adolescence. This is a natural and beautiful thing, but it should be treated with truth and caution. Xiaoli doesn't want to see Xiaoming dating other girls. She is only kind to Li Ming, which shows that she doesn't know how to associate with boys and doesn't choose the right way. So the correct answer is C.