1. Introduction
Along with the developments in the field of humanities in general, and language teaching in particular, ESP as an approach to teaching courses like English for the students of physics, engineering, etc. has run its way of progress after World War II. Nowadays ESP which is based on learner needs, interests and motivations is exercised everywhere in the world as an independent field and has its own proponents. A majority of graduates and undergraduates are now compelled to learn English since it is the key language to the international currencies of science, technology and commerce. The main purpose of such learning for the students having specific purposes is to acquire the ability to read the appropriate related literature and also scientific manuals in their own fields. To establish such a reading ability, material developers and text designers have prepared different kinds of textbooks for ESP students in their field of study; the quality and suitability of reading materials have always been under examination different interested investigators, among whom are the pragmatic scholars.