链的中间 meaning in English

middle-of-chain

This means that elements cannot be added to or removed from the middle or end of the hash chain - elements can only be added at the beginning , and removal involves cloning all or part of the chain and updating the list head pointer
这就意味着不能将元素添加到hash链的中间或末尾，或者从hash链的中间或末尾删除元素而只能从hash链的开头添加元素，并且删除操作包括克隆整个链或链的一部分并更新列表的头指针。