参考答案：

　 一、、1. Once　　　 2.　not　　　 3. found　　　4.　said　　　 5. How

　　6. happening　　7.　them　　　8.　as　　　 9. please　　　10. doesn’t

　　二、1. D　　 2. B　　 3. F　　　4. E　　　5.C

　　三、1. have lived　 2. broke into　　3. have happened　　4. have been　　5. has

　　四、1.taught himself　 2. so; that　　3. were shown　　4. Which; is　　 5. will you

　　五、A)略。

　　B) One possible version:

　　During the holiday I took part in a special summer camp with my classmates. There we made some new friends who were senior students from Canver, a town on the Thames, which s to the east of London.

　　As hosts, we showed them round many places of interest in Beijing, such as the Palace Museum, the Great Wall and the Summer Palace and told them about the changes taking place in Beijing. And they said Beijing was quite different from what they heard of and t was as beautiful as Canver.

　　Meanwhile, we improved our spoken English with their help.

　　I think the summer camp is of great value.