B.
It is known that the compass was first invented in China.
这里是一个主语从句,it做形式上的主语,真正的主语是that the compass was first invented in China这个从句.由于这是一个主语从句,所以that不能省略.
A选项缺少that C选项 语态以及引导词不符 D选项如果改为AS KNOWN TO ALL THAT 才对
B.
It is known that the compass was first invented in China.
这里是一个主语从句,it做形式上的主语,真正的主语是that the compass was first invented in China这个从句.由于这是一个主语从句,所以that不能省略.
A选项缺少that C选项 语态以及引导词不符 D选项如果改为AS KNOWN TO ALL THAT 才对