Dear ...,
How is it going? I am glad to have received your letter. You said you wanted to know sth. about how the middle school students spent their summer holiday. I am happy to tell you sth. about that.
Firstly, we still consider it important to study and have a good lesure. In order to catch others, we have to study in our summer holiday. After all, it is the time of rest. So we spend certain time travelling or playing with our friends.
Secondly, we often help our parents with housework and work on the fields. Besides, we take part in social activities to help others.
In a word, great changes have taken place in China as well as in the middle school students.