在What made him proud was that more than 80% of the fruit had been fresh一句中，What made him proud 是主语从句，that more than 80% of the fruit had been fresh是表语从句。本句结构属于：主语（从句）＋be+表语（从句）

你的疑问是：如果What made him proud 是主语从句，那它就属于“从句”的性质了，所以句子就没有“主句”了，对不对？通俗地说吧，其实“主句”也是一种从句，只不过它是“主要的从句”，所以我们就叫它“主句”了。