导读目的:了解现代自然科学的重要特点;学习本文从事物的相互关系着眼安排说明顺序的方法;学习本文下定义、分类和举例说明事物的方法。导读步骤:这是一篇介绍现代 Objectives: To understand the important features of modern natural sciences; to study this article, to take into account the relationship between things; to arrange the order of explanation; to learn how to define, classify, and illustrate things in this article. Guide steps: This is an introduction to modern times