it seems that的句型中的it是什么成分

it seems that的句型中的it是什么成分 有没有It seems to do 的句型?还是 it seems that 请问这个句型it seems +adj + that 句型It seems, 和It appears that,有何异同? it seems that 的用法 it seems that的用法 it seems that和it seems as if的区别? it seems as if 和it seems that的区别 It seems (that).引导的是什么从句啊?这个句型属于系表结构么 It seems that it seems that 用法 有没有It seems to be 的句型 It seems that 与It's sure的区别 it seem that和it seem like的区别seems it seems that he is ill与it seems that he were ill 的区别? it seems that等于什么? It seems to us that 句型转化it seems that nobody knew anything about the matternobody seems _____ _______ _______ anything about the matter