某带头结点的单链表的头指针为head，判定该链表为非空的条件是（）。

B． head->next==NULL

C． head!=NULL

D． head->next==head

A、h == NULL;

B、h->next == NULL;

C、h->next == h;

D、h != NULL;

A、head->next==NULL

B、head==NULL

C、head->next==head

D、head!=NULL

A、H->next==NULL

B、H==NULL

C、H->next==H

D、H指向未确定

已知L是非空单链表，head是链表的头指针，且所有结点都已具有如下形式的结构定义：struct node { int data; struct node *next; }*p; 若要删除头结点，则下面正确的语句序列是

A、p = head; head = p->next; free(p);

B、head = head->next; free(head);

C、p = head->next; free(p);

D、head = head->next; p = head; free(p);

已知L是非空单链表，head是链表的头指针，且所有结点都已具有如下形式的结构定义：struct node { int data; struct node *next; }*p; 若要删除头结点，则下面正确的语句序列是

A、p = head; head = p->next; free(p);

B、head = head->next; free(head);

C、p = head->next; free(p);

D、head = head->next; p = head; free(p);

已知L是非空单链表，head是链表的头指针，且所有结点都已具有如下形式的结构定义：struct node { int data; struct node *next; }*p; 若要删除头结点，则下面正确的语句序列是

A、p = head; head = p->next; free(p);

B、head = head->next; free(head);

C、p = head->next; free(p);

D、head = head->next; p = head; free(p);