This is the 4th edition of "Introduction to English Problem Solving." There is almost no writing in it. Notes: * I have a cat (I will try my best to prevent cat hair from getting in). * I will reply within 24 hours whenever possible. * I will ship within a week unless there are circumstances (I will write about any circumstances in my profile). There may be some minor bending or folding, and it has been stored at home, so please purchase only if you understand this!