Except for the shortage of teacher, the lack of classroom and relevant equipment is also what we are endeavouring to solve right now, which we will be so grateful if you could bring some aid to relieve.

这是一个错误百出的句子，见红色部分。其实句子里面没有嵌入式定语从句。这是定语从句的关系代词用在条件从句中（作 relieve 的宾语），这个现象是可以的。不过，bring 用词不当，改为provide。

except for 用词错误，改为in addition to, besides, apart from，因为这种短缺是包括在后面这些不利因素之内的，不是排除在外。此外，teacher 和 classroom 用复数。后面最好不宜使用这种人为的蹩脚的定语从句。应另外写一句。

修改如下：

In addition to the shortage of teachers, the lack of classrooms and relevant equipment is also what we are endeavouring to solve right now. If you could provide some help, we will be very grateful.

关于定语从句的关系代词，作从句成分、而不是主句成分的例句：

We have a problem, which we will be grateful if you can help to resolve.

which 作 if 从句 resolve 的宾语。

我们有一个问题，如果你能帮忙解决，我们将不胜感激。