Question

在名词性从句中，that不是无实际意义，不做成分的吗为什么在这个句子中可作为代词：One of the most impo

在名词性从句中，that不是无实际意义，不做成分的吗为什么在这个句子中可作为代词：One of the most important questions they had to considerwas THAT of public health.

Answer 1

此句并非名词性从句，因为that of public health并不是句子，that在这里是代词，指代句子前面出现的question。

Answer 2

One of the most important questions they had to consider / was THAT of public health.
加主语从句的That应该变成这样
（That) One of the most important questions they had to consider / was THAT of public health.
后面的that于主语从句无关。

追问

那后面的that是干吗呢