高考单选主语从句+定语从句+插入语 ___ is known to the whole world,the Great Wall,___ back to the Qin Dynasty,attracts tens of thousands of people at home and abroad. A.It;dated B.What;dating CWhich;dated D.As;dating 麻烦告知答案的同时帮分析一下句子成分,我现在已经看乱套了,
As is well known to all, the earth goes around the sun.(注意逗号,也有人说是定语从句的) It is well knwon to all that the earth goes around the sun.(这里没有逗号,that-从句是主语从句)