在宾语从句中，当从句是并列句时，第二个分句前的 that不可省略。以下是具体说明和示例：

一、that的省略规则

that的作用

that在宾语从句中不承担任何语法成分，仅起连接作用。

可省略情况

口语或非正式文体中，当从句为简单句时，that可省略。

当从句为并列句时，第二个分句前的that不可省略。

二、并列句中that不可省略的原因

并列句包含两个或更多独立子句，需通过连词（如and、but、or）连接。若省略第二个分句前的that，会导致句意混淆或语法错误。例如：

正确：

He said that he would leave the next day andthat I should stay to wait for his mother.

错误：He said he would leave the next day and I should stay to wait for his mother.

（错误版本中，第二个that被省略，导致“我应该留下来等他的妈妈”成为“他”说的内容，而非“我”）。

三、补充说明

其他连接词：在demand、order、suggest、insist、decide、request、mand等动词后，宾语从句需用“（should）+动词原形”结构，此时that不可省略。

省略的例外情况：当从句为单一简单句时，that可省略。例如：

正确：She told me that she finished her homework.

省略后：She told me she finished her homework.

四、练习示例

正确：

He insisted that he would call you back andthat we could meet tomorrow.

错误：

He insisted he would call you back and we could meet tomorrow.

正确：

She suggested that we go to the park orwe watch a movie.

错误：

She suggested we go to the park or we watch a movie.

通过以上说明和示例，可清晰理解并列句中that的不可省略性及其作用。