请大家分析这个句子结构正确吗

iamastudent722UID：3455554

As is universally acknowledged, every country has its own religions and taboos, once which are violated, we may be considered awfully bad-mannered and it may even trigger some riots.

我是一个好人UID：3418066

不正确吧，两个主句了。

喵呜~UID：3339380

As is universally acknowledged（as引导从句，但是这个从句里面没有主语）, every country has its own religions and taboos,{ once which are violated, we may be considered awfully bad-mannered and it may even trigger some riots.}这边应该自成一个句子吧，要不然就变成一个句子里面有两个主句了。  其实我语法也不好，不知道我说的是不是正确  

iamastudent722UID：3455554

我也同意啊。 那正确的写法应该是什么呢