求短文改错正解!I once worked as night guard in a factory during sum

求短文改错正解!
I once worked as night guard in a factory during summer vacation .on a rain night,all the lights of the factory went out all at once .I rushed out but could see anything .Fortunately the warned system was direct connected with the police station .after three or four minute four police cars arrived at the front gate,the policeman saw all around the factory,butfound nothing usual.A policeman tells me that the rain must have affected the electricity system or caused a short circuit
Dear Lucy,
I came to America as a student ,I have much to learn your country,your culture,and you style .I take with me more of an understand of you as a people ,but i do not dear to say it i"understand."
Before i came to America i was interested at seeing the differences between our two countries .now I leave with the knowledge of how much they are alike .i recognize our similarities; I respect our difference.I leave America with mix feelings :curiosity to learn more .what have I accomplished in my short stay therefore,I challenge with you.
Study hardly .be curious .be kind .be devoted to ideas.
Be willing to soar to the heights what you fore fathers only dreamed about.
Best wishes
Sincerely yours
Li Ming