I think that it is important to master a foreign language.(同义句转换)

问题描述:

I think that it is important to master a foreign language.(同义句转换)
I think _______ ______ ________ ________ a foreign language.
it important to master,我觉得应该是:it's important to master,你呢?

应该用it important to master
it在这里是形式宾语 因为它在动词think(谓语)后面 所以不是形式主语
因为it在这里是形式宾语 所以 如果在后面加is 那句子中就会有两个谓语 即think和is 这在英语中是不允许的
故 应用it important to master