One possible version：
We had some American exchange students in our school last week. As a host brother. I’d like to share some happy experiences with you.
Upon their arrival we gave the American students a warn welcome, among whom a boy named Tim was to stay with my family for the weekend. When school was over, we took the sub way home, where my parents had already prepared a rich family dinner for Tim. The next day, I acted as a guide, showing Tim around the most famous scenic spots in Beijing, such as the Great Wall and the Bird’s Nest. Wherever he went, he had some photos taken to help memorize this unforgettable trip to China. When finally the time came for us to say goodbye, I gave him a Kite as a souvenir.
I think this activity has benefited me a lot. It was a perfect chance for me both to proactive my oral English and to learn more about America.
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