这句英语,主语是topics吗?主谓宾或者主系表都是什么,从句?

题目

这句英语,主语是topics吗?主谓宾或者主系表都是什么,从句?
Topics such as death,for example,were once considered so upsetting and unpleasant that it was a taboo to even talk about them.

答案

Topics such as death, for example,were once considered so upsetting and unpleasant that it was a taboo to even talk about them. 整个句子直译过来大意是：诸如像死亡这样的这样的话题曾经被认为是如此的令人...