关于it is said that

问题描述:

关于it is said that
我看到有这两个句型:
it is said that...
it has been said that...
我想问
1.这两个句型有什么区别吗?也就是说 会因时态不同 而使用范围也不同吗?
2.从句的时态有规定吗?我看到的例句从句时态跟主句时态好像没有任何关系啊 ,如:
it is said that this book has been translated into many languages.
It has often been said that life is difficult as it is.
3.有没有it was said that
和 it had been said that 呢 如果有,它们之间有什么区别啊?

1.没有区别
2.要从宾语从句的时态来看
3.没有