In fact, the content in each unit is separates completely. However, if learners understand the former units, it makes them more understanding of the latter units, e.g. grammar in unit 6 teaches “Will you …?, Can/Could you …?, Would you … ? for Request” and it also teaches “I’ll for offers” and after that the grammar in unit 7 teaches “I’ll … if …”. If learners know how to use “will” well from unit 6, they will be more understanding if-cause sentence in unit 7 certainly. So, the content sequence of this book is suitable.