Answer keys are available free of charge for a limited number of Cheng & Tsui publications. Because of the sensitive nature of such material, we are only able to offer answer keys to teachers formally affiliated with a school or institution. We are unfortunately unable to offer answer keys to independent learners.
To obtain an answer key for a product published by Cheng & Tsui, please contact us with your name, the school/institution you are associated with, and the name of your course. To expedite the approval process, please also include a link to your school's staff directory, or similar web page that confirms your employment as a teacher.