it is (said) that China is a developing country为什么用said,而不是say,或是says

It is said that. 为什么是It is said that 而不是It said that It is said that that that that that man said is not that thatthat that woman said.翻译 it is said that通常翻译成? It is said that是什么结构 it is said that 什么时态 It is said____ ____ was all ___ he said.It is said that that was all that he said. It is said that that was all that he said.这三个that分别是什么从句? it is said that that was all that he said= it is said that that was what he said这两个句子相等吗? it is said that的固定结构可以改成 it was said that? It is said that there is no weather in Britain. 语句:IT WAS SAID THAT THAT THAT THAT THAT BOY WROTE IS THAT.意思? 英文据说的用法及造句it is said that it is said to beit is said to do 请帮各造些句. It says that ,It is said that和It is reported的意思和区别? it is said that that was the beginning of raising silkworms1:it is said that 2:RAISE为什么加ING “It's said that that that that that man used is wrong.”是什么意思啊? it is said that后加什么时态 it is said that中的TAHT , 可以省吗