Dear Professor Peter Richards,

I am writing on behalf of the Students' Union of our university to invite you to give a lecture on American culture to the freshmen of the English Department. We believe that your expertise and experience in this field will be of great value to our students.

The lecture is scheduled for Tuesday, April 8, 2014. We would be honored if you could join us on this occasion. Please let us know if you are available and willing to accept our invitation.

Thank you for considering our request.

Sincerely,

Li Ming

Chairman of the Students' Union