综合填空
Dear John，
How are you?I’m writing to tell you what I’m d___ in China.I’m on a school t___ and I’m having a good time.At the moment I’m w___on the Great Wall.There are forty students in my school.They are doing different things. Some are taking lots of photos h___.Some areb_____ presents and postcards on sale for their family and friends, some are talking to eacho____.and some are having lunch and l__ in the sun.Now It is time to go now.Weh__ to stand in line and wait for the bus. A__,we are e____ the trip a lot. See you later.