It was ture that 是强调句还是主语从句?

It was true that he had just bought a lamb,he explained,but his lamb was black.

It was ture that 是强调句还是主语从句? 若是主语的话,it指的内容是从that一直到句尾的black吗?

It was true that he had just bought a lamb, he explained, but his lamb was black.

1 一个简单有什么区别强调句型和主语从句外置的方法就是，去掉 it is/was that, 看剩下的部分是不是是一个完整的句子。假如句子结构完整，没多余的成分，则一般为强调句型。

你的句子中去掉it was that 后，形容词true无成分可作，这就排除去强调句型。期望你将来不要再问此类问题，自己用这种办法判断。

2 上句中黑体部分为外置的主语从句（即真的主语从句）。but后为并列分句。这个句子是自由间接引语结构。即引语作为主句，而引述分句（he explained) 以插入语的形式出现, 用逗号和引语分隔。假如改为普通的间接引语，则为如下句子：

He explained it was true that he had just bought a lamb, but that his lamb was black.

这个句子中，引述分句为主句，引语为宾语从句。