Chimpanzees in western Africa's Tai forest crack nuts by placing them on tree roots and striking them with stones,a learned behavior [probablyl unique to chimpanzees in that area].
A.probably unique to
B.probably unique about
C.probably it is unique to
D.that is probably unique with
E.having probably been unique to
请问这个Unique有什么固定搭配吗?我用排除法已经排除了CDE,就是在AB两者之间纠结...