一、非谓语动词概述
非谓语动词是指在句子中不作谓语的动词形式，包括现在分词、过去分词和不定式。在高中英语学习中，非谓语动词的用法是语法教学的重要内容，它能够丰富句子的表达方式，增强句子的表现力。
二、非谓语过去完成时的用法
构成：非谓语过去完成时的构成是“had + 过去分词”。
时间关系：表示在过去某个时间点之前已经完成的动作或状态。
句型结构：
主语 + had + 过去分词 + 宾语/状语
It + was/were + had + 过去分词 + 宾语/状语
三、非谓语过去完成时的具体例子
By the time he finished his homework, he had already read three chapters of the book.
It was when he had finished his work that he realized it was already midnight.
四、非谓语过去完成时的练习
问题1：以下哪个句子使用了非谓语过去完成时？
A. He was reading the book when the bell rang.
B. By the time he got to the library, the book he wanted had already been borrowed.
C. I had finished my meal before I knew it.
答案1：
A. 错误，这是现在分词的用法。
B. 正确，使用了非谓语过去完成时。
C. 错误，这是过去完成时的用法，但不是非谓语形式。
问题2：以下哪个句子使用了非谓语过去完成时来表示原因？
A. He had studied hard, so he passed the exam.
B. He studied hard, because he had to pass the exam.
C. He had to pass the exam, so he studied hard.
答案2：
A. 错误，这是现在分词的用法。
B. 正确，使用了非谓语过去完成时来表示原因。
C. 错误，这是因果关系，但没有使用非谓语过去完成时。
问题3：以下哪个句子使用了非谓语过去完成时来表示结果？
A. He studied hard, and he passed the exam.
B. He had studied hard, so he passed the exam.
C. He passed the exam, because he had studied hard.
答案3：
A. 错误，这是并列句。
B. 正确，使用了非谓语过去完成时来表示结果。
C. 错误，这是因果关系，但没有使用非谓语过去完成时。
