单项选择题

University Physics
University Physics is intended for students of science and engineering. Primary emphasis is on physical principles and problem-solving; historical background and specialized practical applications have been given a place of secondary importance. Many worked-out examples and an extensive collection of problems are included with each chapter.
In this new edition, the basic philosophy and outline and the balance between depth of treatment and breadth of subject-matter coverage are unchanged from previous editions. We have tried to preserve those features that users of previous editions have found desirable, while incorporating a number of changes that should enhance the book’s usefulness.
The textbook is adaptable to a wide variety of course outlines. The entire textbook can be used for an intensive course two or three semesters in length. For a less intensive course, many instructors will want to omit certain chapters or sections to tailor the book to their individual needs. The arrangement of this edition facilitates this kind of flexibility.
Conversely, however, many topics that were regarded a few years ago as of peripheral (外围的、次要的) importance and were omitted from introductory courses have now come to the fore again in the life sciences, earth and space sciences, and environmental problems. An instructor who wishes to stress these kinds of applications will find this textbook a useful source for discussion of the appropriate principles.
In any case, it should be emphasized that instructors should not feel constrained (受约束的) to work straight through the book from cover to cover. Many chapters are, of course, inherently sequential in nature, but within this general limitation instructors should be encouraged to select among the contents those chapters that fit their needs, omitting material that is not relevant to the objectives of a particular course.
Compared with the old one, this new edition ______.