Taiwan belongs to China,（）is known to us.为啥不能用that~

Taiwan belongs to China,（）is known to us.为啥不能用that~ That is known to all,Taiwan belongs to China.改错 ----is well known to us all that Taiwan belongs to China.--- --- is known to us all ,Taiwan is part of china Taiwan, that is known, belongs to our country怎么改错?只有一处错误 改错:Everyone of us knows,Taiwan belongs to China. Taiwan belongs to China,that is everybody knows这句话对吗why? It is known to all that the island belongs to China for___(c ____ is known to everyone that Taiwan is part of China. As is known to us.和It is known to us.后面接什么啊?为啥 （What) is known to us all is that China is a developing coun 1.___ is known to us all is that China is a developing count