此题要求改正所给短文中的错误。

May I have you attention please? I have a little things to tell you. When you have a class here in the language lab, please be here a little early. Change your shoes before enter the lab. Don't bring anything here except your text books. When you are into, please don't touch these machine without permission. Always do as the teacher tell you to. In class you should only speak the English, not Chinese. Recorders can be used make a copy of the listening materials. When class over, turn off your machines and leave the lab one by one.

下面是关于8259A可编程中断控制器的叙述，其中错误的是：

A． 8259A具有将中断源按优先级排队的功能

B． 8259A具有辨认中断源的功能

C． 8259A具有向CPU提供中断向量的功能

D． 两片8259A级联使用时，可将中断源扩展到16级