a short introductory essay preceding the text of a book
同义词：foreword??/??preface
exercising in preparation for strenuous activity
同义词：warm-up??/??tune-up
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。