英语中读完一本书的表达方式有很多种，常见的有以下几种：
"finish a book"，意为“读完一本书”。例句：I finished a book last night. (我昨晚读完了一本书)
"read a book from cover to cover"，意为“从头到尾读完一本书”。例句：I read the book from cover to cover in one day. (我一天就从头到尾读完了这本书)
"devour a book"，意为“吞噬一本书”，强调阅读的迅速和迫切。例句：I devoured that thriller in one sitting. (我一口气就把那本惊悚小说吞噬了)
"get through a book"，意为“读完一本书”。例句：I managed to get through the whole book in a week. (我花了一周的时间读完了整本书)
这些表达方式都是英语的常用表达，来源于英语的日常交流和文学作品中。