本书是数学资优生培养课程丛书中的一本，可供学有余力的学生自学，也可由家长辅导孩子使用。全书共30讲，每讲均有 基础知识 典型例题 巩固拓展 答案详解 四部分。 基础知识 阐述涉及的数学知识、数学方法、数学思想； 典型例题 精选了经典的数学例题或数学竞赛的原题； 巩固拓展 是根据内容配置适量的练习，以便孩子举一反三、自行练习。本书根据一年级孩子的认知水平和知识积累，立足于数学资优生的培养，拓展孩子的数学思维、数学知识，提升孩子的数学素养，是一本适合一年级孩子的数学素质提升类辅导资料。
四季教育根据多年的教学培养实践，依据小学生年龄和思维特点，汇聚了上海一些*秀中小学数学教育专家、数学教师的经验和智慧特编写本系列丛书。此丛书1 5年级各一套，编排系统性强，以四季教育开设的思维训练课程为参照，分 夏 、 秋 、 冬 、 春 四部分，每年夏季是新学年的开始，次年春季结束，每一部分各有10个专题，2个综合练习，共12讲。它包含了小学数学所涉及的所有知识点，深入浅出，由易到难逐步过渡，重点部分深入讲解。
This book is intended to serve as a textbook for a course in algebraic topology at the beginning graduate level. The main topics covered are the classification of pact 2-manifolds, the fundamental group, covering spaces, singular homology theory, and singular cohomology theory (including cup products and the duality theorems of Poincare and Alexander). It consists of material from the first five chapters of the author's earlier book Algebraic Topology: An Introduction (GTM 56) together with almost all of his book Singular Homology Theory (GTM 70). This material from the two earlier books has been revised, corrected, and brought up to date. There is enough here for a full-year course. The author has tried to give a straightforward treatment of the subject matter, stripped of all unnecessary definitions, terminology, and technical machinery. He has also tried, wherever feasible, to emphasize the geometric motivation behind the various concepts. Several applications of the methods of
