Write a short letter to your friend Liu Yang, who is a freshman in another college and doesn’t know how to prepare for the CET-4. Tell him:
1. You have passed the CET-4;
2. what you have done in preparation for the test;
3. encourage your friend to be confident and work hard for the test in the next term.
Do not sign your own name at the end of your letter. Use "Li Hua" instead. You do not need to write the address.