过去进行时的被动语态表示过去某个时刻正在进行或者发生的被动性的动作。其结构形式为：“was/were being + 过去分词”。在这个结构中，“was/were”是过去进行时的助动词，表示动作发生的时间是过去；“being”是现在分词，用来表示“正在进行中”的意思；“过去分词”则是需要被动形式的动词，表示动作的承受者。

例如：

1. He said that the man was being operated on.

2. He told me that a new station was being built.

3. The project was being completed by the team last night.

4. anotherbridgewasbeingbuiltoverthechangjiangriverthen.

5. A bridge was being built by the workers at that time.

这些例句都清晰地展示了过去进行时的被动语态的用法，即通过“was/were being + 过去分词”的结构来描述过去某个时间点或时间段正在进行的被动动作。