Dear John，
get this news from your mother and know you must be absent for half a month from the classes. Do be careful while you are ill.
Don’t worry about your lesson and I am willing to help you learn it when you return. We are best friends so I will never allow you to fall behind.
You can watch television or listen to radio programs to help pass the time and you some funny cartoons.
be happy when you are back.
Your truly,
Li Ming