How to find and measure bias in textbooks Book

Textbook has a good flow, however I felt that some items were introduced out of order and that there was not enough grammar practice provided. I'd like to see clearer examples at the beginning of the exercises, in order to show students an example of what the exercise is looking for.

This is an introductory textbook, and is very good for someone who is completely new to the language. I feel that a more challenging/advanced textbook is needed for mastery of the language in non-introductory college courses. The grammar provided is a solid foundation, but the vocabulary is missing. The simple past should be introduced sooner and thus carried through the rest of the text with each introduction of a new verb.