Is the book of Tianyi Chengkao reliable?

Reliable. According to the inquiry of Guangdong Chengkao. com。

1 The books published by Tianyi Chengkao cover a wide range and serve exams in various fields such as postgraduate entrance examination, teacher recruitment and civil servants. Among them, reference books such as College English Test Paper of CET-4 and CET-6, Detailed Explanation of Mathematics for Ten Years, etc. are well received by candidates.

2. The books that Tianyi has tested are rich in teachers, rich in content, and the division of questions is very detailed. The book has many key contents and comprehensive knowledge points.