Where some people a hard nut to crack, but who also can not be replaced .什么意思谁知道

问题描述:

Where some people a hard nut to crack, but who also can not be replaced .
什么意思谁知道

有些人很倔强,但是他们也是无可替代的.

是病句吧!
hard nut to crack 是很麻烦,很难解决的问题
我想这句的意思是,有些人很倔强,但是他们也是无可替代的.