Given the task definition and input, reply with output. Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

Which is the or no make that what is the receptor that killer T cells use to bind to specific antigens that are complexed with the MHC 1 class receptor of another cell?
What is the receptor that killer T cells use to bind to specific antigens that are complexed with the MHC Class 1 receptor of another cell?