I heard that the teaching reference book is the 4th volume.

Author: He Fusheng et al.
Publisher:
Publish Date: 2006-05-01
Features: This book is the teaching reference for the Listening and Speaking (Volume 4) of the New English Course (4th Edition). It mainly includes hints on training points, cultural background explanations, reference answers to exercises in the Student's Book, and listening text materials for Section 3.
Target Audience: Suitable for teachers and students using the New English Course (4th Edition) Listening and Speaking (Volume 4).