it一般不用作名词短语的先行主语。但当用作主语的名词之后有定语从句修饰时，则可以用it作形式主语，而把受定语从句修饰的名词后移。《牛津英语用法指南》就有如下说明：

在非正式文体里，it可以充当名词+关系从句的先行主语。

It’s wonderful the enthusiasm that the children show. 孩子们表现出的热情高涨极了。

the way... 也常用于这种结构中。

It’s amazing the way (that) they work together. 他们在一起工作的方式，真令人惊讶。

It worries me the way he keeps changing his mind.

现代英语，the way 可以用作连词，直接引导名词性从句，the way 的意思相当于 how 或 that。所以，划线部分是主语从句，故用 it 作形式主语。

It worries me the way he keeps changing his mind. 等于：

It worries me how he keeps changing his mind.

It worries me that he keeps changing his mind.

又如：

It was boring the way he kept complaining to his wife.

It was boring how he kept complaining to his wife.

It was boring that he kept complaining to his wife.