“这是我见过的最好的书”英文怎么说？

一楼是对的
六楼？……过去完成时和现在式连用……这个句子 显然是错的……

This is the best book that I have ever seen.

this is the most wonderful book i have ever met.

This is the best book that i had ever seen.

This is the best book that I have ever seen.
I have never seen a better book before.