Mr.He had changed his mind and decided to open the mould exactly as original sample

Mr.He had changed his mind and decided to open the mould exactly as original sample

这句用的had对吗？ 为什么？
为什么也可以用has? 用had和has各有什么不同？ 定重谢！

Mr Smith told me that he had got( )to do at the moment. Mr Reed made up his mind to devote all he had to ___ some schools for poor children. Mr Smith made up his mind to devote all he had to( )some schools for poor students. 寻求He,Mr. DJ he had had......怎么连读 he had to be hungry 1. where had he been? he had words with me... He had fun going shopping. he had had to make thebreak he had been rhinking about for so long .如何理解