My goal in writing this book is to help Chinese English students learn the most common way Americans usually express themselves in everyday English. I spent hundreds of hours saying the phrases and sentences over and over in my mind to try to find the most natural spoken structures. I believe most students use written English forms more than the daily spoken English forms. Therefore, in this book you will find expressions such as "have to" instead of "must"; "a lot of" instead of "much" or "many". Teacher Fu and I also spent a lot of time trying to explain some differences __ some textbook sentence patterns and daily spoken English.

What preposition should be used to fill in the above blank, in or between?