it is (said) that China is a developing country为什么用said,而不是say,或是says
问题描述：
it is (said) that China is a developing country
为什么用said,而不是say,或是says
答
因为有is,be+过去分词表示被动,意思是据说.
如果要用say 或者says的话,主语应该变一变,成：
they say that China is a developing country
或者he says that China is a developing country