【答案解析】
Dear Li Hua,
It is with great regret that I am writing this letter of apology to you.
I now realize that I was entirely unjust in saying yon were an unreliable person. My criticism was solely based on misunderstanding. You promised to tutor my neighbour"s child in English on Saturday but didn"t come. Later it came to me that you were helping send an old lady to hospital.
How regretful I am when I know I had wronged you! It"s my sincere hope that my unfair remarks will not harm our friendship. Now I beg to withdraw my rash statement about you. Please accept my sincere apology.