One possible version:
Dear Bruce,
I was glad to hear from you and now I would like to tell you something that you mentioned. Yesterday we had an activity about health problems and a famous nutrition expert was invited to give a lecture.
The expert referred to the terrible situation of people’s health and the reasons for it. By showing us some pictures, he introduced some serious diseases caused by eating too much food with lots of fat, oil, salt and sugar. We learned more about the dangers of junk food through the activity.
After the lecture, we had a heated discussion. We decide to say goodbye to junk food, and exercise more to make our bodies stronger.
I hope you can tell me more about your story.
Best wishes.
Yours,
Li Hua
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