循环链表的主要优点是( )。

A．不再需要头指针了

B．从表中任一结点出发都能访问到整个链表

C．在进行插入、删除运算时，能更好的保证链表不断开

D．已知某个结点的位置后，能够容易的找到它的直接前件

If you ________ yesterday，you ________ with your mother now.

A．set off; would talk

B．had set off; would be talking

C．set off; would have talked

D．had set off; would talk